condition mean min max ZT0-3 24.7 24.7 24.7 ZT4-7 6.6 6.6 6.6 ZT8-11 9.05 9.05 9.05 ZT12-15 11.5 11.5 11.5 ZT16-19 28.75 28.75 28.75 ZT20-23 8.1 8.1 8.1