condition mean min max ZT0-3 17.15 17.15 17.15 ZT4-7 9.8 9.8 9.8 ZT8-11 30.85 30.85 30.85 ZT12-15 17.700000000000003 17.700000000000003 17.700000000000003 ZT16-19 22.5 22.5 22.5 ZT20-23 9.0 9.0 9.0