condition mean min max ZT0-3 17.5 17.5 17.5 ZT4-7 6.8 6.8 6.8 ZT8-11 5.25 5.25 5.25 ZT12-15 20.099999999999998 20.099999999999998 20.099999999999998 ZT16-19 9.95 9.95 9.95 ZT20-23 16.849999999999998 16.849999999999998 16.849999999999998