condition mean min max ZT0-3 5.493995 3.478155 7.31053 ZT4-7 3.496945 3.496945 3.496945 ZT8-11 2.559055 2.559055 2.559055 ZT12-15 12.8365875 8.781575 16.8916 ZT16-19 10.218544999999999 10.218544999999999 10.218544999999999 ZT20-23 8.774625 8.774625 8.774625