condition mean min max ZT0-3 8.6 8.6 8.6 ZT4-7 20.3 20.3 20.3 ZT8-11 14.5 14.5 14.5 ZT12-15 5.6 5.6 5.6 ZT16-19 9.55 9.55 9.55 ZT20-23 24.85 24.85 24.85