condition mean min max ZT0-3 2.3 2.3 2.3 ZT4-7 4.5 4.5 4.5 ZT8-11 7.65 7.65 7.65 ZT12-15 21.45 21.45 21.45 ZT16-19 2.6 2.6 2.6 ZT20-23 3.95 3.95 3.95