condition mean min max ZT0-3 9.487625000000001 9.487625000000001 9.487625000000001 ZT4-7 6.16016 6.16016 6.16016 ZT8-11 7.050795 7.050795 7.050795 ZT12-15 7.452065 7.452065 7.452065 ZT16-19 9.510365 9.510365 9.510365 ZT20-23 8.945975 8.945975 8.945975