condition mean min max ZT0-3 8.446746 8.446746 8.446746 ZT4-7 9.843160000000001 9.843160000000001 9.843160000000001 ZT8-11 8.1911255 8.1911255 8.1911255 ZT12-15 8.780051 8.780051 8.780051 ZT16-19 7.5980695 7.5980695 7.5980695 ZT20-23 8.7400055 8.7400055 8.7400055