condition mean min max ZT0-3 13.0 13.0 13.0 ZT4-7 3.6 3.6 3.6 ZT8-11 5.1 5.1 5.1 ZT12-15 8.15 8.15 8.15 ZT16-19 7.85 7.85 7.85 ZT20-23 36.4 36.4 36.4