condition mean min max ZT0-3 16.700000000000003 16.700000000000003 16.700000000000003 ZT4-7 28.3 28.3 28.3 ZT8-11 22.950000000000003 22.950000000000003 22.950000000000003 ZT12-15 33.3 33.3 33.3 ZT16-19 16.95 16.95 16.95 ZT20-23 22.65 22.65 22.65