Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1750 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 1970 | Thousand metric tons of contained nitrogen | 12.57% |
| 2005 | 1700 | Thousand metric tons of contained nitrogen | -13.71% |
| 2006 | 1800 | Thousand metric tons of contained nitrogen | 5.88% |
| 2007 | 1800 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 1800 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 1800 | Thousand metric tons of contained nitrogen | 0.00% |
