condition mean min max ZT0-3 10.06584 10.06584 10.06584 ZT4-7 7.1585149999999995 7.1585149999999995 7.1585149999999995 ZT8-11 8.751225 8.751225 8.751225 ZT12-15 11.022245 11.022245 11.022245 ZT16-19 12.8118 12.8118 12.8118 ZT20-23 11.530149999999999 11.530149999999999 11.530149999999999