condition mean min max ZT0-3 9.55 9.55 9.55 ZT4-7 31.3 31.3 31.3 ZT8-11 2.85 2.85 2.85 ZT12-15 16.35 16.35 16.35 ZT16-19 18.0 18.0 18.0 ZT20-23 11.65 11.65 11.65