condition mean min max ZT0-3 7.6 7.6 7.6 ZT4-7 10.7 10.7 10.7 ZT8-11 12.75 12.75 12.75 ZT12-15 14.05 14.05 14.05 ZT16-19 32.85 32.85 32.85 ZT20-23 13.25 13.25 13.25