condition mean min max ZT0-3 23.739925 22.16265 25.3172 ZT4-7 29.6524 29.6524 29.6524 ZT8-11 30.915399999999998 30.915399999999998 30.915399999999998 ZT12-15 0 0 0 ZT16-19 32.26645 32.26645 32.26645 ZT20-23 30.328850000000003 30.328850000000003 30.328850000000003