condition mean min max ZT0-3 19.9312 19.37365 20.48875 ZT4-7 20.23065 20.23065 20.23065 ZT8-11 18.74645 18.74645 18.74645 ZT12-15 0 0 0 ZT16-19 24.06145 24.06145 24.06145 ZT20-23 25.85995 25.85995 25.85995