condition mean min max ZT0-3 1.7 1.7 1.7 ZT4-7 1.8 1.8 1.8 ZT8-11 18.05 18.05 18.05 ZT12-15 5.1 5.1 5.1 ZT16-19 2.6 2.6 2.6 ZT20-23 3.4 3.4 3.4