condition mean min max ZT0-3 18.755168 18.755168 18.755168 ZT4-7 29.550654 29.550654 29.550654 ZT8-11 46.5670265 46.5670265 46.5670265 ZT12-15 49.570128999999994 49.570128999999994 49.570128999999994 ZT16-19 28.518229500000004 28.518229500000004 28.518229500000004 ZT20-23 22.836301499999998 22.836301499999998 22.836301499999998