condition mean min max ZT0-3 50.63428333333333 25.41205 68.69295 ZT4-7 21.7295 21.7295 21.7295 ZT8-11 17.530050000000003 17.530050000000003 17.530050000000003 ZT12-15 23.127025 20.8091 25.44495 ZT16-19 33.403099999999995 33.403099999999995 33.403099999999995 ZT20-23 58.48665 58.48665 58.48665