condition mean min max ZT0-3 7.0 7.0 7.0 ZT4-7 6.2 6.2 6.2 ZT8-11 4.15 4.15 4.15 ZT12-15 15.15 15.15 15.15 ZT16-19 17.7 17.7 17.7 ZT20-23 5.85 5.85 5.85