condition mean min max ZT0-3 6.7 6.7 6.7 ZT4-7 9.1 9.1 9.1 ZT8-11 17.0 17.0 17.0 ZT12-15 29.6 29.6 29.6 ZT16-19 14.05 14.05 14.05 ZT20-23 4.8 4.8 4.8