condition mean min max ZT0-3 6.27577 6.27577 6.27577 ZT4-7 5.144915 5.144915 5.144915 ZT8-11 3.347775 3.347775 3.347775 ZT12-15 4.0897749999999995 4.0897749999999995 4.0897749999999995 ZT16-19 9.448805 9.448805 9.448805 ZT20-23 5.851380000000001 5.851380000000001 5.851380000000001