condition mean min max ZT0-3 18.24825 18.24825 18.24825 ZT4-7 15.386299999999999 15.386299999999999 15.386299999999999 ZT8-11 15.24515 15.24515 15.24515 ZT12-15 14.684650000000001 14.684650000000001 14.684650000000001 ZT16-19 17.0434 17.0434 17.0434 ZT20-23 17.8037 17.8037 17.8037