condition mean min max ZT0-3 1.8673951666666666 0.392401 3.585295 ZT4-7 0.3839615 0.3839615 0.3839615 ZT8-11 1.2105124999999999 1.2105124999999999 1.2105124999999999 ZT12-15 1.9239927499999998 1.2876604999999999 2.5603249999999997 ZT16-19 1.9251200000000002 1.9251200000000002 1.9251200000000002 ZT20-23 4.34297 4.34297 4.34297