condition mean min max ZT0-3 4.3 4.3 4.3 ZT4-7 3.3 3.3 3.3 ZT8-11 7.75 7.75 7.75 ZT12-15 4.5 4.5 4.5 ZT16-19 3.3 3.3 3.3 ZT20-23 4.6 4.6 4.6