condition mean min max ZT0-3 21.00955 13.9986 27.00205 ZT4-7 7.921595 7.921595 7.921595 ZT8-11 10.021275 10.021275 10.021275 ZT12-15 13.030825 12.106135 13.955515 ZT16-19 20.76135 20.76135 20.76135 ZT20-23 31.61575 31.61575 31.61575