condition mean min max ZT0-3 26.05627322 25.037143810000003 27.07540263 ZT4-7 27.927528636666665 25.56495877 30.290098503333333 ZT8-11 24.1299953 22.36388068 25.89610992 ZT12-15 37.256606835 35.64436282 38.86885085 ZT16-19 42.452880305 41.82893549 43.07682512 ZT20-23 42.915767020000004 42.21552854666667 43.61600549333333