condition mean min max ZT0-3 1.8463405 1.8463405 1.8463405 ZT4-7 1.0582285 1.0582285 1.0582285 ZT8-11 1.2302183333333332 1.2302183333333332 1.2302183333333332 ZT12-15 1.8467547500000001 1.8467547500000001 1.8467547500000001 ZT16-19 1.0880214 1.0880214 1.0880214 ZT20-23 0.80900375 0.80900375 0.80900375