condition mean min max ZT0-3 19.397404905000002 18.23740267 20.55740714 ZT4-7 13.447300322 12.370876669 14.523723975 ZT8-11 17.9317740675 16.370029045 19.49351909 ZT12-15 19.89653303 17.91850081 21.87456525 ZT16-19 18.9951763825 18.65673561 19.333617155 ZT20-23 22.259828765 21.353420805 23.166236725