* Although the U.S. Geological Survey collects data every five years, there are a few years of delay in releasing the data in order to fully process it.
Years Available: 1985, 1990, 1995, 2000, 2005, 2010, 2015
Permanent Link: http://data.sagepub.com/sagestats/6493
General Notes: *Median value gives the value for the "average" county for this metric, the 50th percentile of all counties reporting data. **Includes both saline and fresh water.