condition mean min max ZT0-3 38.25405 30.6033 43.802049999999994 ZT4-7 24.2359 24.2359 24.2359 ZT8-11 26.816499999999998 26.816499999999998 26.816499999999998 ZT12-15 34.14005 32.3555 35.9246 ZT16-19 37.97395 37.97395 37.97395 ZT20-23 45.53885 45.53885 45.53885