condition mean min max ZT0-3 5.39333641725 5.033439468 5.7532333665 ZT4-7 4.39809858275 4.383235953 4.4129612125 ZT8-11 3.59956823125 3.5144162915 3.684720171 ZT12-15 5.2681076565 3.8370206315 6.6991946815 ZT16-19 8.5988156945 7.667009063 9.530622326 ZT20-23 12.32413261 11.904892045 12.743373175