condition mean min max ZT0-3 14.814975 13.48925 16.140700000000002 ZT4-7 20.8823 20.8823 20.8823 ZT8-11 21.9545 21.9545 21.9545 ZT12-15 0 0 0 ZT16-19 24.1248 24.1248 24.1248 ZT20-23 25.349899999999998 25.349899999999998 25.349899999999998