condition mean min max ZT0-3 50.73091666666666 23.3969 66.75094999999999 ZT4-7 14.9252 14.9252 14.9252 ZT8-11 15.005849999999999 15.005849999999999 15.005849999999999 ZT12-15 21.479875 17.14105 25.8187 ZT16-19 29.6482 29.6482 29.6482 ZT20-23 56.9273 56.9273 56.9273