condition mean min max ZT0-3 7.7 7.7 7.7 ZT4-7 3.3 3.3 3.3 ZT8-11 26.5 26.5 26.5 ZT12-15 2.0 2.0 2.0 ZT16-19 5.8 5.8 5.8 ZT20-23 10.25 10.25 10.25