condition mean min max ZT0-3 10.15 10.15 10.15 ZT4-7 1.8 1.8 1.8 ZT8-11 2.4 2.4 2.4 ZT12-15 16.5 16.5 16.5 ZT16-19 15.4 15.4 15.4 ZT20-23 8.1 8.1 8.1