condition mean min max ZT0-3 1.8414549999999998 1.4454799999999999 2.23743 ZT4-7 1.8531750000000002 1.8531750000000002 1.8531750000000002 ZT8-11 0.8403395 0.8403395 0.8403395 ZT12-15 0 0 0 ZT16-19 1.527365 1.527365 1.527365 ZT20-23 2.51458 2.51458 2.51458