condition mean min max ZT0-3 12.600000000000001 12.600000000000001 12.600000000000001 ZT4-7 15.2 15.2 15.2 ZT8-11 14.5 14.5 14.5 ZT12-15 9.3 9.3 9.3 ZT16-19 9.649999999999999 9.649999999999999 9.649999999999999 ZT20-23 18.849999999999998 18.849999999999998 18.849999999999998