condition mean min max ZT0-3 4.61645133 4.1656997669999996 5.067202893 ZT4-7 9.758641732000001 7.447581804 12.06970166 ZT8-11 14.762527245000001 13.3371159 16.18793859 ZT12-15 12.41306480925 12.071970405000002 12.7541592135 ZT16-19 10.575727789999998 9.808550799999999 11.34290478 ZT20-23 15.641660589999999 14.18605191 17.097269269999998