condition mean min max ZT0-3 2.7 2.7 2.7 ZT4-7 3.1 3.1 3.1 ZT8-11 2.7 2.7 2.7 ZT12-15 5.9 5.9 5.9 ZT16-19 10.6 10.6 10.6 ZT20-23 5.0 5.0 5.0