condition mean min max ZT0-3 3.7378400000000003 3.7378400000000003 3.7378400000000003 ZT4-7 2.420945 2.420945 2.420945 ZT8-11 3.174835 3.174835 3.174835 ZT12-15 5.96755 5.96755 5.96755 ZT16-19 7.09428 7.09428 7.09428 ZT20-23 5.33836 5.33836 5.33836