condition mean min max ZT0-3 3.7432783333333335 3.086845 4.44784 ZT4-7 3.2173499999999997 3.2173499999999997 3.2173499999999997 ZT8-11 4.700975 4.700975 4.700975 ZT12-15 7.560122499999999 6.536795 8.58345 ZT16-19 5.64156 5.64156 5.64156 ZT20-23 5.14591 5.14591 5.14591