condition mean min max ZT0-3 36.477075 27.84995 45.1042 ZT4-7 17.63035 17.63035 17.63035 ZT8-11 15.45275 15.45275 15.45275 ZT12-15 0 0 0 ZT16-19 19.10215 19.10215 19.10215 ZT20-23 25.294249999999998 25.294249999999998 25.294249999999998