condition mean min max ZT0-3 9.05 9.05 9.05 ZT4-7 3.6 3.6 3.6 ZT8-11 1.85 1.85 1.85 ZT12-15 20.45 20.45 20.45 ZT16-19 20.45 20.45 20.45 ZT20-23 19.1 19.1 19.1