condition mean min max ZT0-3 18.0 18.0 18.0 ZT4-7 6.3 6.3 6.3 ZT8-11 6.25 6.25 6.25 ZT12-15 5.15 5.15 5.15 ZT16-19 5.7 5.7 5.7 ZT20-23 11.8 11.8 11.8