condition mean min max ZT0-3 13.75 13.75 13.75 ZT4-7 12.7 12.7 12.7 ZT8-11 9.05 9.05 9.05 ZT12-15 11.45 11.45 11.45 ZT16-19 11.9 11.9 11.9 ZT20-23 3.4 3.4 3.4