condition mean min max ZT0-3 4.9 4.9 4.9 ZT4-7 8.3 8.3 8.3 ZT8-11 2.5 2.5 2.5 ZT12-15 5.95 5.95 5.95 ZT16-19 4.65 4.65 4.65 ZT20-23 9.15 9.15 9.15