condition mean min max ZT0-3 12.775166666666667 11.71215 14.15955 ZT4-7 14.412600000000001 14.412600000000001 14.412600000000001 ZT8-11 18.0957 18.0957 18.0957 ZT12-15 23.7062 22.724649999999997 24.68775 ZT16-19 22.5701 22.5701 22.5701 ZT20-23 15.30765 15.30765 15.30765