condition mean min max ZT0-3 2.2 2.2 2.2 ZT4-7 11.6 11.6 11.6 ZT8-11 22.85 22.85 22.85 ZT12-15 5.0 5.0 5.0 ZT16-19 4.55 4.55 4.55 ZT20-23 3.95 3.95 3.95