List the maximum, minimum and average number of used kb in screen mode.
SELECT max(used_kb) , min(used_kb) , avg(used_kb) FROM screen_mode;
SELECT max(used_kb) , min(used_kb) , avg(used_kb) FROM screen_mode;
[{'max(used_kb)': 20.0, 'min(used_kb)': 8.0, 'avg(used_kb)': 14.857142857142858}]