condition mean min max ZT0-3 9.3 9.3 9.3 ZT4-7 2.8 2.8 2.8 ZT8-11 2.05 2.05 2.05 ZT12-15 3.4000000000000004 3.4000000000000004 3.4000000000000004 ZT16-19 22.099999999999998 22.099999999999998 22.099999999999998 ZT20-23 18.9 18.9 18.9