condition mean min max ZT0-3 2.05 2.05 2.05 ZT4-7 7.0 7.0 7.0 ZT8-11 4.75 4.75 4.75 ZT12-15 10.7 10.7 10.7 ZT16-19 8.95 8.95 8.95 ZT20-23 21.6 21.6 21.6