condition mean min max ZT0-3 5.277806666666667 4.998555 5.542605 ZT4-7 3.2129700000000003 3.2129700000000003 3.2129700000000003 ZT8-11 3.3283300000000002 3.3283300000000002 3.3283300000000002 ZT12-15 4.968299999999999 3.685415 6.2511849999999995 ZT16-19 3.624065 3.624065 3.624065 ZT20-23 5.61695 5.61695 5.61695