For each country, what is the average elevation of that country's airports?
SELECT avg(elevation) ,  country FROM airports GROUP BY country
SELECT avg(elevation) ,  country FROM airports GROUP BY country
[{'avg(elevation)': 3732.4, 'country': 'Afghanistan'}, {'avg(elevation)': 281.4, 'country': 'Albania'}, {'avg(elevation)': 1449.6046511627908, 'country': 'Algeria'}, {'avg(elevation)': 71.0, 'country': 'American Samoa'}, {'avg(elevation)': 2408.25, 'country': 'Angola'}, {'avg(elevation)': 127.0, 'country': 'Anguilla'}, {'avg(elevation)': 1831.857142857143, 'country': 'Antarctica'}, {'avg(elevation)': 38.5, 'country': 'Antigua and Barbuda'}, {'avg(elevation)': 1099.6170212765958, 'country': 'Argentina'}, {'avg(elevation)': 3124.4, 'country': 'Armenia'}, {'avg(elevation)': 60.0, 'country': 'Aruba'}, {'avg(elevation)': 484.5878378378378, 'country': 'Australia'}, {'avg(elevation)': 1505.2105263157894, 'country': 'Austria'}, {'avg(elevation)': 1171.5714285714287, 'country': 'Azerbaijan'}, {'avg(elevation)': 10.303030303030303, 'country': 'Bahamas'}, {'avg(elevation)': 71.0, 'country': 'Bahrain'}, {'avg(elevation)': 40.5, 'country': 'Bangladesh'}, {'avg(elevation)': 169.0, 'country': 'Barbados'}, {'avg(elevation)': 462.2, 'country': 'Belarus'}, {'avg(elevation)': 430.25, 'country': 'Belgium'}, {'avg(elevation)': 49.0, 'country': 'Belize'}, {'avg(elevation)': 19.0, 'country': 'Benin'}, {'avg(elevation)': 12.0, 'country': 'Bermuda'}, {'avg(elevation)': 5599.0, 'country': 'Bhutan'}, {'avg(elevation)': 4340.04347826087, 'country': 'Bolivia'}, {'avg(elevation)': 762.0, 'country': 'Bosnia and Herzegovina'}, {'avg(elevation)': 3147.153846153846, 'country': 'Botswana'}, {'avg(elevation)': 1144.08547008547, 'country': 'Brazil'}, {'avg(elevation)': 9.0, 'country': 'British Indian Ocean Territory'}, {'avg(elevation)': 11.0, 'country': 'British Virgin Islands'}, {'avg(elevation)': 40.0, 'country': 'Brunei'}, {'avg(elevation)': 501.1818181818182, 'country': 'Bulgaria'}, {'avg(elevation)': 1274.0, 'country': 'Burkina Faso'}, {'avg(elevation)': 907.3720930232558, 'country': 'Burma'}, {'avg(elevation)': 2582.0, 'country': 'Burundi'}, {'avg(elevation)': 55.55555555555556, 'country': 'Cambodia'}, {'avg(elevation)': 2314.0, 'country': 'Cameroon'}, {'avg(elevation)': 854.884892086331, 'country': 'Canada'}, {'avg(elevation)': 266.2857142857143, 'country': 'Cape Verde'}, {'avg(elevation)': 6.333333333333333, 'country': 'Cayman Islands'}, {'avg(elevation)': 1568.5, 'country': 'Central African Republic'}, {'avg(elevation)': 1258.6666666666667, 'country': 'Chad'}, {'avg(elevation)': 1156.2954545454545, 'country': 'Chile'}, {'avg(elevation)': 1789.2055555555555, 'country': 'China'}, {'avg(elevation)': 916.0, 'country': 'Christmas Island'}, {'avg(elevation)': 10.0, 'country': 'Cocos (Keeling) Islands'}, {'avg(elevation)': 1733.5135135135135, 'country': 'Colombia'}, {'avg(elevation)': 58.5, 'country': 'Comoros'}, {'avg(elevation)': 727.3333333333334, 'country': 'Congo (Brazzaville)'}, {'avg(elevation)': 1936.840909090909, 'country': 'Congo (Kinshasa)'}, {'avg(elevation)': 21.625, 'country': 'Cook Islands'}, {'avg(elevation)': 461.06666666666666, 'country': 'Costa Rica'}, {'avg(elevation)': 728.8571428571429, 'country': "Cote d'Ivoire"}, {'avg(elevation)': 599.8571428571429, 'country': 'Croatia'}, {'avg(elevation)': 140.5, 'country': 'Cuba'}, {'avg(elevation)': 132.25, 'country': 'Cyprus'}, {'avg(elevation)': 1053.7083333333333, 'country': 'Czech Republic'}, {'avg(elevation)': 71.25925925925925, 'country': 'Denmark'}, {'avg(elevation)': 121.33333333333333, 'country': 'Djibouti'}, {'avg(elevation)': 43.0, 'country': 'Dominica'}, {'avg(elevation)': 433.38461538461536, 'country': 'Dominican Republic'}, {'avg(elevation)': 673.6666666666666, 'country': 'East Timor'}, {'avg(elevation)': 2421.6857142857143, 'country': 'Ecuador'}, {'avg(elevation)': 546.125, 'country': 'Egypt'}, {'avg(elevation)': 1061.0, 'country': 'El Salvador'}, {'avg(elevation)': 44.5, 'country': 'Equatorial Guinea'}, {'avg(elevation)': 2633.6666666666665, 'country': 'Eritrea'}, {'avg(elevation)': 59.666666666666664, 'country': 'Estonia'}, {'avg(elevation)': 5416.689655172414, 'country': 'Ethiopia'}, {'avg(elevation)': 159.5, 'country': 'Falkland Islands'}, {'avg(elevation)': 168.4, 'country': 'Faroe Islands'}, {'avg(elevation)': 60.94117647058823, 'country': 'Fiji'}, {'avg(elevation)': 340.2352941176471, 'country': 'Finland'}, {'avg(elevation)': 658.0467289719626, 'country': 'France'}, {'avg(elevation)': 226.16666666666666, 'country': 'French Guiana'}, {'avg(elevation)': 62.94444444444444, 'country': 'French Polynesia'}, {'avg(elevation)': 803.2307692307693, 'country': 'Gabon'}, {'avg(elevation)': 95.0, 'country': 'Gambia'}, {'avg(elevation)': 1356.6, 'country': 'Georgia'}, {'avg(elevation)': 610.6265560165975, 'country': 'Germany'}, {'avg(elevation)': 632.5, 'country': 'Ghana'}, {'avg(elevation)': 15.0, 'country': 'Gibraltar'}, {'avg(elevation)': 327.4909090909091, 'country': 'Greece'}, {'avg(elevation)': 116.54545454545455, 'country': 'Greenland'}, {'avg(elevation)': 41.0, 'country': 'Grenada'}, {'avg(elevation)': 26.285714285714285, 'country': 'Guadeloupe'}, {'avg(elevation)': 462.5, 'country': 'Guam'}, {'avg(elevation)': 2540.2, 'country': 'Guatemala'}, {'avg(elevation)': 313.0, 'country': 'Guernsey'}, {'avg(elevation)': 1214.5, 'country': 'Guinea'}, {'avg(elevation)': 64.66666666666667, 'country': 'Guinea-Bissau'}, {'avg(elevation)': 626.9230769230769, 'country': 'Guyana'}, {'avg(elevation)': 109.66666666666667, 'country': 'Haiti'}, {'avg(elevation)': 492.75, 'country': 'Honduras'}, {'avg(elevation)': 61.666666666666664, 'country': 'Hong Kong'}, {'avg(elevation)': 476.6666666666667, 'country': 'Hungary'}, {'avg(elevation)': 105.85, 'country': 'Iceland'}, {'avg(elevation)': 991.688, 'country': 'India'}, {'avg(elevation)': 516.312, 'country': 'Indonesia'}, {'avg(elevation)': 2697.0864197530864, 'country': 'Iran'}, {'avg(elevation)': 581.375, 'country': 'Iraq'}, {'avg(elevation)': 143.1764705882353, 'country': 'Ireland'}, {'avg(elevation)': 52.0, 'country': 'Isle of Man'}, {'avg(elevation)': 385.3125, 'country': 'Israel'}, {'avg(elevation)': 317.7926829268293, 'country': 'Italy'}, {'avg(elevation)': 24.833333333333332, 'country': 'Jamaica'}, {'avg(elevation)': 200.8235294117647, 'country': 'Japan'}, {'avg(elevation)': 277.0, 'country': 'Jersey'}, {'avg(elevation)': 7.0, 'country': 'Johnston Atoll'}, {'avg(elevation)': 1917.0, 'country': 'Jordan'}, {'avg(elevation)': 879.9166666666666, 'country': 'Kazakhstan'}, {'avg(elevation)': 3391.5714285714284, 'country': 'Kenya'}, {'avg(elevation)': 4.611111111111111, 'country': 'Kiribati'}, {'avg(elevation)': 362.3333333333333, 'country': 'Kuwait'}, {'avg(elevation)': 3295.2, 'country': 'Kyrgyzstan'}, {'avg(elevation)': 1566.9166666666667, 'country': 'Laos'}, {'avg(elevation)': 163.0, 'country': 'Latvia'}, {'avg(elevation)': 1060.0, 'country': 'Lebanon'}, {'avg(elevation)': 5851.0, 'country': 'Lesotho'}, {'avg(elevation)': 25.333333333333332, 'country': 'Liberia'}, {'avg(elevation)': 795.2352941176471, 'country': 'Libya'}, {'avg(elevation)': 295.77777777777777, 'country': 'Lithuania'}, {'avg(elevation)': 1234.0, 'country': 'Luxembourg'}, {'avg(elevation)': 20.0, 'country': 'Macau'}, {'avg(elevation)': 1547.0, 'country': 'Macedonia'}, {'avg(elevation)': 624.0, 'country': 'Madagascar'}, {'avg(elevation)': 2588.375, 'country': 'Malawi'}, {'avg(elevation)': 264.225, 'country': 'Malaysia'}, {'avg(elevation)': 163.45454545454547, 'country': 'Maldives'}, {'avg(elevation)': 1023.5, 'country': 'Mali'}, {'avg(elevation)': 150.0, 'country': 'Malta'}, {'avg(elevation)': 9.875, 'country': 'Marshall Islands'}, {'avg(elevation)': 16.0, 'country': 'Martinique'}, {'avg(elevation)': 625.4545454545455, 'country': 'Mauritania'}, {'avg(elevation)': 140.5, 'country': 'Mauritius'}, {'avg(elevation)': 23.0, 'country': 'Mayotte'}, {'avg(elevation)': 2257.2289156626507, 'country': 'Mexico'}, {'avg(elevation)': 30.75, 'country': 'Micronesia'}, {'avg(elevation)': 13.0, 'country': 'Midway Islands'}, {'avg(elevation)': 452.4, 'country': 'Moldova'}, {'avg(elevation)': 4546.384615384615, 'country': 'Mongolia'}, {'avg(elevation)': 80.5, 'country': 'Montenegro'}, {'avg(elevation)': 550.0, 'country': 'Montserrat'}, {'avg(elevation)': 1482.3636363636363, 'country': 'Morocco'}, {'avg(elevation)': 1277.9473684210527, 'country': 'Mozambique'}, {'avg(elevation)': 499.0, 'country': 'Myanmar'}, {'avg(elevation)': 3011.75, 'country': 'Namibia'}, {'avg(elevation)': 22.0, 'country': 'Nauru'}, {'avg(elevation)': 4076.9375, 'country': 'Nepal'}, {'avg(elevation)': 60.26923076923077, 'country': 'Netherlands'}, {'avg(elevation)': 50.2, 'country': 'Netherlands Antilles'}, {'avg(elevation)': 103.81818181818181, 'country': 'New Caledonia'}, {'avg(elevation)': 415.9807692307692, 'country': 'New Zealand'}, {'avg(elevation)': 220.41666666666666, 'country': 'Nicaragua'}, {'avg(elevation)': 1239.7142857142858, 'country': 'Niger'}, {'avg(elevation)': 979.4545454545455, 'country': 'Nigeria'}, {'avg(elevation)': 209.0, 'country': 'Niue'}, {'avg(elevation)': 371.0, 'country': 'Norfolk Island'}, {'avg(elevation)': 69.25, 'country': 'North Korea'}, {'avg(elevation)': 364.3333333333333, 'country': 'Northern Mariana Islands'}, {'avg(elevation)': 300.44262295081967, 'country': 'Norway'}, {'avg(elevation)': 312.5, 'country': 'Oman'}, {'avg(elevation)': 1513.5, 'country': 'Pakistan'}, {'avg(elevation)': 176.0, 'country': 'Palau'}, {'avg(elevation)': 320.0, 'country': 'Palestine'}, {'avg(elevation)': 81.0, 'country': 'Panama'}, {'avg(elevation)': 1469.1538461538462, 'country': 'Papua New Guinea'}, {'avg(elevation)': 631.375, 'country': 'Paraguay'}, {'avg(elevation)': 3124.095238095238, 'country': 'Peru'}, {'avg(elevation)': 182.609375, 'country': 'Philippines'}, {'avg(elevation)': 452.07894736842104, 'country': 'Poland'}, {'avg(elevation)': 440.59375, 'country': 'Portugal'}, {'avg(elevation)': 50.6, 'country': 'Puerto Rico'}, {'avg(elevation)': 82.5, 'country': 'Qatar'}, {'avg(elevation)': 1097.3333333333333, 'country': 'Reunion'}, {'avg(elevation)': 628.8947368421053, 'country': 'Romania'}, {'avg(elevation)': 542.7394957983194, 'country': 'Russia'}, {'avg(elevation)': 5044.333333333333, 'country': 'Rwanda'}, {'avg(elevation)': 278.0, 'country': 'Saint Helena'}, {'avg(elevation)': 92.0, 'country': 'Saint Kitts and Nevis'}, {'avg(elevation)': 18.0, 'country': 'Saint Lucia'}, {'avg(elevation)': 18.5, 'country': 'Saint Pierre and Miquelon'}, {'avg(elevation)': 23.2, 'country': 'Saint Vincent and the Grenadines'}, {'avg(elevation)': 63.0, 'country': 'Samoa'}, {'avg(elevation)': 312.0, 'country': 'Sao Tome and Principe'}, {'avg(elevation)': 1903.340909090909, 'country': 'Saudi Arabia'}, {'avg(elevation)': 130.55555555555554, 'country': 'Senegal'}, {'avg(elevation)': 662.6, 'country': 'Serbia'}, {'avg(elevation)': 9.5, 'country': 'Seychelles'}, {'avg(elevation)': 335.14285714285717, 'country': 'Sierra Leone'}, {'avg(elevation)': 46.833333333333336, 'country': 'Singapore'}, {'avg(elevation)': 938.75, 'country': 'Slovakia'}, {'avg(elevation)': 862.2, 'country': 'Slovenia'}, {'avg(elevation)': 12.565217391304348, 'country': 'Solomon Islands'}, {'avg(elevation)': 1114.375, 'country': 'Somalia'}, {'avg(elevation)': 3071.3229166666665, 'country': 'South Africa'}, {'avg(elevation)': 145.58620689655172, 'country': 'South Korea'}, {'avg(elevation)': 1781.5, 'country': 'South Sudan'}, {'avg(elevation)': 991.1290322580645, 'country': 'Spain'}, {'avg(elevation)': 133.5, 'country': 'Sri Lanka'}, {'avg(elevation)': 1498.888888888889, 'country': 'Sudan'}, {'avg(elevation)': 330.75, 'country': 'Suriname'}, {'avg(elevation)': 41.0, 'country': 'Svalbard'}, {'avg(elevation)': 2075.0, 'country': 'Swaziland'}, {'avg(elevation)': 424.94805194805195, 'country': 'Sweden'}, {'avg(elevation)': 1729.878048780488, 'country': 'Switzerland'}, {'avg(elevation)': 1159.1666666666667, 'country': 'Syria'}, {'avg(elevation)': 146.75, 'country': 'Taiwan'}, {'avg(elevation)': 1947.75, 'country': 'Tajikistan'}, {'avg(elevation)': 2694.0, 'country': 'Tanzania'}, {'avg(elevation)': 359.66, 'country': 'Thailand'}, {'avg(elevation)': 793.5, 'country': 'Togo'}, {'avg(elevation)': 151.33333333333334, 'country': 'Tonga'}, {'avg(elevation)': 48.0, 'country': 'Trinidad and Tobago'}, {'avg(elevation)': 308.25, 'country': 'Tunisia'}, {'avg(elevation)': 1871.611111111111, 'country': 'Turkey'}, {'avg(elevation)': 520.2, 'country': 'Turkmenistan'}, {'avg(elevation)': 9.333333333333334, 'country': 'Turks and Caicos Islands'}, {'avg(elevation)': 9.0, 'country': 'Tuvalu'}, {'avg(elevation)': 3833.8, 'country': 'Uganda'}, {'avg(elevation)': 523.6666666666666, 'country': 'Ukraine'}, {'avg(elevation)': 137.41176470588235, 'country': 'United Arab Emirates'}, {'avg(elevation)': 180.8641975308642, 'country': 'United Kingdom'}, {'avg(elevation)': 1113.1512195121952, 'country': 'United States'}, {'avg(elevation)': 238.36363636363637, 'country': 'Uruguay'}, {'avg(elevation)': 1182.3076923076924, 'country': 'Uzbekistan'}, {'avg(elevation)': 129.48275862068965, 'country': 'Vanuatu'}, {'avg(elevation)': 760.1052631578947, 'country': 'Venezuela'}, {'avg(elevation)': 487.5, 'country': 'Vietnam'}, {'avg(elevation)': 32.333333333333336, 'country': 'Virgin Islands'}, {'avg(elevation)': 14.0, 'country': 'Wake Island'}, {'avg(elevation)': 49.5, 'country': 'Wallis and Futuna'}, {'avg(elevation)': 2485.0, 'country': 'West Bank'}, {'avg(elevation)': 197.66666666666666, 'country': 'Western Sahara'}, {'avg(elevation)': 2088.7272727272725, 'country': 'Yemen'}, {'avg(elevation)': 3356.9166666666665, 'country': 'Zambia'}, {'avg(elevation)': 3270.5333333333333, 'country': 'Zimbabwe'}]