condition mean min max ZT0-3 6.5239503797500005 6.309958625 6.737942134500001 ZT4-7 8.3376674825 6.852788258 9.822546707 ZT8-11 8.337116262999999 8.178982214 8.495250312 ZT12-15 6.367616304749999 5.61789452 7.1173380895 ZT16-19 9.16246874625 7.7880687805 10.536868712 ZT20-23 16.3328672925 12.878488560000001 19.787246025