condition mean min max ZT0-3 4.4 4.4 4.4 ZT4-7 9.3 9.3 9.3 ZT8-11 10.5 10.5 10.5 ZT12-15 7.75 7.75 7.75 ZT16-19 4.35 4.35 4.35 ZT20-23 30.5 30.5 30.5