condition mean min max ZT0-3 2.6 2.6 2.6 ZT4-7 16.7 16.7 16.7 ZT8-11 6.5 6.5 6.5 ZT12-15 3.2 3.2 3.2 ZT16-19 11.85 11.85 11.85 ZT20-23 17.95 17.95 17.95