condition mean min max ZT0-3 7.2029499999999995 7.2029499999999995 7.2029499999999995 ZT4-7 5.447229999999999 5.447229999999999 5.447229999999999 ZT8-11 5.893095 5.893095 5.893095 ZT12-15 6.086795 6.086795 6.086795 ZT16-19 6.97752 6.97752 6.97752 ZT20-23 7.2536249999999995 7.2536249999999995 7.2536249999999995