condition mean min max ZT0-3 3.302426666666667 2.904185 3.9015450000000005 ZT4-7 4.978325 4.978325 4.978325 ZT8-11 6.395035 6.395035 6.395035 ZT12-15 12.87135 12.594750000000001 13.14795 ZT16-19 8.421935 8.421935 8.421935 ZT20-23 7.818315 7.818315 7.818315