condition mean min max ZT0-3 4.25 4.25 4.25 ZT4-7 3.0 3.0 3.0 ZT8-11 5.1 5.1 5.1 ZT12-15 15.6 15.6 15.6 ZT16-19 12.15 12.15 12.15 ZT20-23 6.6 6.6 6.6