condition mean min max ZT0-3 6.9 6.9 6.9 ZT4-7 45.2 45.2 45.2 ZT8-11 12.15 12.15 12.15 ZT12-15 10.25 10.25 10.25 ZT16-19 6.15 6.15 6.15 ZT20-23 30.0 30.0 30.0