Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 20 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 20 | Thousand metric tons of contained nitrogen | 0.00% |
| 2005 | 20 | Thousand metric tons of contained nitrogen | 0.00% |
| 2006 | 20 | Thousand metric tons of contained nitrogen | 0.00% |
| 2007 | 20 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 18 | Thousand metric tons of contained nitrogen | -10.00% |
| 2009 | 22 | Thousand metric tons of contained nitrogen | 22.22% |
| 2010 | 27 | Thousand metric tons of contained nitrogen | 22.73% |
| 2011 | 28 | Thousand metric tons of contained nitrogen | 3.70% |
| 2012 | 30 | Thousand metric tons of contained nitrogen | 7.14% |
