condition mean min max ZT0-3 3.2 3.2 3.2 ZT4-7 2.2 2.2 2.2 ZT8-11 5.1 5.1 5.1 ZT12-15 12.9 12.9 12.9 ZT16-19 4.35 4.35 4.35 ZT20-23 6.1 6.1 6.1