What is the average number of attendance at home games for each year?
SELECT YEAR ,  avg(attendance) FROM home_game GROUP BY YEAR;
SELECT YEAR ,  avg(attendance) FROM home_game GROUP BY YEAR;
[{'year': 1871, 'avg(attendance)': 17125.0}, {'year': 1872, 'avg(attendance)': 14603.333333333334}, {'year': 1873, 'avg(attendance)': 0.0}, {'year': 1874, 'avg(attendance)': 27249.7}, {'year': 1875, 'avg(attendance)': 17329.391304347828}, {'year': 1876, 'avg(attendance)': 0.0}, {'year': 1877, 'avg(attendance)': 0.0}, {'year': 1878, 'avg(attendance)': 0.0}, {'year': 1879, 'avg(attendance)': 0.0}, {'year': 1880, 'avg(attendance)': 0.0}, {'year': 1881, 'avg(attendance)': 0.0}, {'year': 1882, 'avg(attendance)': 0.0}, {'year': 1883, 'avg(attendance)': 0.0}, {'year': 1884, 'avg(attendance)': 0.0}, {'year': 1885, 'avg(attendance)': 0.0}, {'year': 1886, 'avg(attendance)': 11856.35294117647}, {'year': 1887, 'avg(attendance)': 18591.666666666668}, {'year': 1888, 'avg(attendance)': 8186.380952380952}, {'year': 1889, 'avg(attendance)': 6767.571428571428}, {'year': 1890, 'avg(attendance)': 10271.057142857142}, {'year': 1891, 'avg(attendance)': 2324.0}, {'year': 1892, 'avg(attendance)': 4512.642857142857}, {'year': 1893, 'avg(attendance)': 9379.07142857143}, {'year': 1894, 'avg(attendance)': 143202.375}, {'year': 1895, 'avg(attendance)': 9883.333333333334}, {'year': 1896, 'avg(attendance)': 0.0}, {'year': 1897, 'avg(attendance)': 9875.0}, {'year': 1898, 'avg(attendance)': 350.0}, {'year': 1899, 'avg(attendance)': 3200.0}, {'year': 1900, 'avg(attendance)': 36116.125}, {'year': 1901, 'avg(attendance)': 7859.0}, {'year': 1902, 'avg(attendance)': 0.0}, {'year': 1903, 'avg(attendance)': 0.0}, {'year': 1904, 'avg(attendance)': 0.0}, {'year': 1905, 'avg(attendance)': 0.0}, {'year': 1906, 'avg(attendance)': 46664.75}, {'year': 1907, 'avg(attendance)': 0.0}, {'year': 1908, 'avg(attendance)': 5284.6875}, {'year': 1909, 'avg(attendance)': 0.0}, {'year': 1910, 'avg(attendance)': 0.0}, {'year': 1911, 'avg(attendance)': 117353.38888888889}, {'year': 1912, 'avg(attendance)': 0.0}, {'year': 1913, 'avg(attendance)': 0.0}, {'year': 1914, 'avg(attendance)': 211425.64}, {'year': 1915, 'avg(attendance)': 153360.2}, {'year': 1916, 'avg(attendance)': 55500.0}, {'year': 1917, 'avg(attendance)': 220268.875}, {'year': 1918, 'avg(attendance)': 46148.75}, {'year': 1919, 'avg(attendance)': 213044.1875}, {'year': 1920, 'avg(attendance)': 280158.1176470588}, {'year': 1921, 'avg(attendance)': 340739.625}, {'year': 1922, 'avg(attendance)': 317164.375}, {'year': 1923, 'avg(attendance)': 435409.8125}, {'year': 1924, 'avg(attendance)': 501204.8125}, {'year': 1925, 'avg(attendance)': 470832.6875}, {'year': 1926, 'avg(attendance)': 238276.375}, {'year': 1927, 'avg(attendance)': 488246.4705882353}, {'year': 1928, 'avg(attendance)': 294843.25}, {'year': 1929, 'avg(attendance)': 336567.82352941175}, {'year': 1930, 'avg(attendance)': 213375.82352941178}, {'year': 1931, 'avg(attendance)': 285558.4117647059}, {'year': 1932, 'avg(attendance)': 221597.83333333334}, {'year': 1933, 'avg(attendance)': 295785.1875}, {'year': 1934, 'avg(attendance)': 189549.0}, {'year': 1935, 'avg(attendance)': 350890.6875}, {'year': 1936, 'avg(attendance)': 436795.5882352941}, {'year': 1937, 'avg(attendance)': 437536.1176470588}, {'year': 1938, 'avg(attendance)': 476012.22222222225}, {'year': 1939, 'avg(attendance)': 604727.8823529412}, {'year': 1940, 'avg(attendance)': 628654.4705882353}, {'year': 1941, 'avg(attendance)': 560421.8823529412}, {'year': 1942, 'avg(attendance)': 485573.64705882355}, {'year': 1943, 'avg(attendance)': 465679.4117647059}, {'year': 1944, 'avg(attendance)': 524242.9411764706}, {'year': 1945, 'avg(attendance)': 651439.2352941176}, {'year': 1946, 'avg(attendance)': 1019072.2777777778}, {'year': 1947, 'avg(attendance)': 1286085.625}, {'year': 1948, 'avg(attendance)': 1319362.0}, {'year': 1949, 'avg(attendance)': 1285012.375}, {'year': 1950, 'avg(attendance)': 1088765.5625}, {'year': 1951, 'avg(attendance)': 1024580.3125}, {'year': 1952, 'avg(attendance)': 912397.625}, {'year': 1953, 'avg(attendance)': 929984.5625}, {'year': 1954, 'avg(attendance)': 1033169.8125}, {'year': 1955, 'avg(attendance)': 1041463.875}, {'year': 1956, 'avg(attendance)': 991736.7647058824}, {'year': 1957, 'avg(attendance)': 1007885.2941176471}, {'year': 1958, 'avg(attendance)': 1087706.5625}, {'year': 1959, 'avg(attendance)': 1203611.5625}, {'year': 1960, 'avg(attendance)': 1248884.6875}, {'year': 1961, 'avg(attendance)': 1051839.388888889}, {'year': 1962, 'avg(attendance)': 1074105.2}, {'year': 1963, 'avg(attendance)': 1039067.8}, {'year': 1964, 'avg(attendance)': 1064345.1}, {'year': 1965, 'avg(attendance)': 1127733.0}, {'year': 1966, 'avg(attendance)': 1205586.5714285714}, {'year': 1967, 'avg(attendance)': 1199437.7}, {'year': 1968, 'avg(attendance)': 1093400.5238095238}, {'year': 1969, 'avg(attendance)': 1094134.84}, {'year': 1970, 'avg(attendance)': 1103714.0}, {'year': 1971, 'avg(attendance)': 1218456.6666666667}, {'year': 1972, 'avg(attendance)': 1145264.7083333333}, {'year': 1973, 'avg(attendance)': 1255066.875}, {'year': 1974, 'avg(attendance)': 1249488.4166666667}, {'year': 1975, 'avg(attendance)': 1241784.4583333333}, {'year': 1976, 'avg(attendance)': 1304951.4583333333}, {'year': 1977, 'avg(attendance)': 1510126.3461538462}, {'year': 1978, 'avg(attendance)': 1562493.2307692308}, {'year': 1979, 'avg(attendance)': 1677201.423076923}, {'year': 1980, 'avg(attendance)': 1656938.7307692308}, {'year': 1981, 'avg(attendance)': 1023446.3461538461}, {'year': 1982, 'avg(attendance)': 1717054.423076923}, {'year': 1983, 'avg(attendance)': 1745448.6538461538}, {'year': 1984, 'avg(attendance)': 1721233.7307692308}, {'year': 1985, 'avg(attendance)': 1801622.3846153845}, {'year': 1986, 'avg(attendance)': 1828231.7692307692}, {'year': 1987, 'avg(attendance)': 2001087.1153846155}, {'year': 1988, 'avg(attendance)': 2038187.423076923}, {'year': 1989, 'avg(attendance)': 2052794.9259259258}, {'year': 1990, 'avg(attendance)': 2114356.576923077}, {'year': 1991, 'avg(attendance)': 2187885.346153846}, {'year': 1992, 'avg(attendance)': 2151571.1153846155}, {'year': 1993, 'avg(attendance)': 2509234.0714285714}, {'year': 1994, 'avg(attendance)': 1785157.5357142857}, {'year': 1995, 'avg(attendance)': 1804337.857142857}, {'year': 1996, 'avg(attendance)': 2005524.2333333334}, {'year': 1997, 'avg(attendance)': 2180498.0}, {'year': 1998, 'avg(attendance)': 2278377.7741935486}, {'year': 1999, 'avg(attendance)': 2197934.625}, {'year': 2000, 'avg(attendance)': 2275673.625}, {'year': 2001, 'avg(attendance)': 2341054.3870967743}, {'year': 2002, 'avg(attendance)': 2264819.8666666667}, {'year': 2003, 'avg(attendance)': 2182286.2258064514}, {'year': 2004, 'avg(attendance)': 2212707.484848485}, {'year': 2005, 'avg(attendance)': 2497232.6666666665}, {'year': 2006, 'avg(attendance)': 2534515.8333333335}, {'year': 2007, 'avg(attendance)': 2484490.0}, {'year': 2008, 'avg(attendance)': 2382495.8484848486}, {'year': 2009, 'avg(attendance)': 2447339.6}, {'year': 2010, 'avg(attendance)': 2283591.625}, {'year': 2011, 'avg(attendance)': 2368569.9032258065}, {'year': 2012, 'avg(attendance)': 2414815.0967741935}, {'year': 2013, 'avg(attendance)': 2387968.935483871}, {'year': 2014, 'avg(attendance)': 2378697.4838709678}]