condition mean min max ZT0-3 12.0 12.0 12.0 ZT4-7 6.7 6.7 6.7 ZT8-11 11.5 11.5 11.5 ZT12-15 30.55 30.55 30.55 ZT16-19 7.45 7.45 7.45 ZT20-23 15.2 15.2 15.2