condition mean min max ZT0-3 8.05 8.05 8.05 ZT4-7 5.1 5.1 5.1 ZT8-11 15.25 15.25 15.25 ZT12-15 22.2 22.2 22.2 ZT16-19 17.25 17.25 17.25 ZT20-23 2.0 2.0 2.0