condition mean min max ZT0-3 1.4688683333333334 1.334 1.61094 ZT4-7 0.658771 0.658771 0.658771 ZT8-11 1.707065 1.707065 1.707065 ZT12-15 4.880155 4.7766649999999995 4.983645 ZT16-19 4.310840000000001 4.310840000000001 4.310840000000001 ZT20-23 3.78436 3.78436 3.78436