condition mean min max ZT0-3 4.7 4.7 4.7 ZT4-7 6.5 6.5 6.5 ZT8-11 3.95 3.95 3.95 ZT12-15 1.85 1.85 1.85 ZT16-19 2.95 2.95 2.95 ZT20-23 17.1 17.1 17.1