condition mean min max ZT0-3 1.75 1.75 1.75 ZT4-7 1.3 1.3 1.3 ZT8-11 18.099999999999998 18.099999999999998 18.099999999999998 ZT12-15 1.25 1.25 1.25 ZT16-19 2.1 2.1 2.1 ZT20-23 13.35 13.35 13.35