As if anyone needed more proof that the Denver housing market is tight, a recent survey shows that Colorado is tied for the fourth-lowest residential vacancy in the country.

A study by Attom Data Solutions shows that only 0.69% of residential properties in Colorado are vacant, compared to the national rate of 1.58%. Colorado tied with North Dakota for the fourth-lowest vacancy rate in the country, behind New Hampshire (.42%), Vermont (.39%) and South Dakota (.25%).

The Attom report analyzed properties with one to four residential units, rather than large multifamily projects and apartment buildings. It showed 11,311 unoccupied residential properties in Colorado currently, compared with 14,230 at the end of the third quarter in 2015.

Douglas County has the second-lowest vacancy rate (.1%) of U.S. counties with at least 50,000 residential properties.

Fort Collins tied San Jose, Calif., for the lowest vacancy rate (.24%) in metro areas of at least 100,000 residential properties.

By contrast, states with the highest vacancy rates were Mississippi (3%); Michigan (2.94%); Indiana (2.77%); Oklahoma (2.73%); and Alabama (2.56%).