condition mean min max ZT0-3 17.644825 7.119425 23.9975 ZT4-7 7.93724 7.93724 7.93724 ZT8-11 10.55733 10.55733 10.55733 ZT12-15 11.280047499999998 10.679145 11.880949999999999 ZT16-19 15.5445 15.5445 15.5445 ZT20-23 27.346 27.346 27.346