condition mean min max ZT0-3 8.3 8.3 8.3 ZT4-7 23.0 23.0 23.0 ZT8-11 12.3 12.3 12.3 ZT12-15 18.25 18.25 18.25 ZT16-19 12.95 12.95 12.95 ZT20-23 16.7 16.7 16.7