Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 353.5 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 420 | Thousand metric tons of contained nitrogen | 18.81% |
| 2005 | 300 | Thousand metric tons of contained nitrogen | -28.57% |
| 2006 | 350 | Thousand metric tons of contained nitrogen | 16.67% |
| 2007 | 350 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 350 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 300 | Thousand metric tons of contained nitrogen | -14.29% |
| 2010 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
| 2011 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
| 2012 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
