condition mean min max ZT0-3 3.25 3.25 3.25 ZT4-7 1.6 1.6 1.6 ZT8-11 12.2 12.2 12.2 ZT12-15 3.95 3.95 3.95 ZT16-19 2.6 2.6 2.6 ZT20-23 2.55 2.55 2.55