condition mean min max ZT0-3 2.85 2.85 2.85 ZT4-7 3.5 3.5 3.5 ZT8-11 8.75 8.75 8.75 ZT12-15 18.7 18.7 18.7 ZT16-19 4.05 4.05 4.05 ZT20-23 11.25 11.25 11.25