condition mean min max ZT0-3 1.5 1.5 1.5 ZT4-7 6.4 6.4 6.4 ZT8-11 10.0 10.0 10.0 ZT12-15 3.5 3.5 3.5 ZT16-19 10.55 10.55 10.55 ZT20-23 4.0 4.0 4.0