condition mean min max ZT0-3 4.466368333333333 1.8898549999999998 8.760584999999999 ZT4-7 5.746840000000001 5.746840000000001 5.746840000000001 ZT8-11 2.9655 2.9655 2.9655 ZT12-15 4.599595 1.938285 7.260905 ZT16-19 2.354515 2.354515 2.354515 ZT20-23 2.75344 2.75344 2.75344