condition mean min max ZT0-3 5.75 5.75 5.75 ZT4-7 6.7 6.7 6.7 ZT8-11 7.15 7.15 7.15 ZT12-15 5.2 5.2 5.2 ZT16-19 5.35 5.35 5.35 ZT20-23 4.8 4.8 4.8