The percentage of residential addresses for which the United States Postal Service has identified as being unoccupied (no mail collection) for a period of at least 90 days or longer. These properties may be habitable, but are not currently being occupied. It is important to note that a single residential property can contain more than one address. Source: U.S. Postal Service, U.S. Department of Housing and Urban Development Years Available: 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020