condition mean min max ZT0-3 4.86923 4.68536 5.053100000000001 ZT4-7 2.267715 2.267715 2.267715 ZT8-11 2.2588150000000002 2.2588150000000002 2.2588150000000002 ZT12-15 0 0 0 ZT16-19 3.9030249999999995 3.9030249999999995 3.9030249999999995 ZT20-23 3.9225600000000003 3.9225600000000003 3.9225600000000003