condition mean min max ZT0-3 7.1 7.1 7.1 ZT4-7 28.9 28.9 28.9 ZT8-11 13.15 13.15 13.15 ZT12-15 12.4 12.4 12.4 ZT16-19 7.25 7.25 7.25 ZT20-23 18.7 18.7 18.7