condition mean min max ZT0-3 15.078783333333332 10.95485 18.170099999999998 ZT4-7 13.97475 13.97475 13.97475 ZT8-11 18.1304 18.1304 18.1304 ZT12-15 20.285249999999998 19.126649999999998 21.443849999999998 ZT16-19 22.6694 22.6694 22.6694 ZT20-23 22.6998 22.6998 22.6998