condition mean min max ZT0-3 50.75 50.75 50.75 ZT4-7 30.1 30.1 30.1 ZT8-11 35.15 35.15 35.15 ZT12-15 42.849999999999994 42.849999999999994 42.849999999999994 ZT16-19 23.700000000000003 23.700000000000003 23.700000000000003 ZT20-23 30.85 30.85 30.85