condition mean min max ZT0-3 7.1 7.1 7.1 ZT4-7 4.5 4.5 4.5 ZT8-11 10.25 10.25 10.25 ZT12-15 7.05 7.05 7.05 ZT16-19 20.7 20.7 20.7 ZT20-23 10.8 10.8 10.8