Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 231.600006103516 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 274 | Thousand metric tons of contained nitrogen | 18.31% |
| 2005 | 275 | Thousand metric tons of contained nitrogen | 0.36% |
| 2006 | 275 | Thousand metric tons of contained nitrogen | 0.00% |
| 2007 | 300 | Thousand metric tons of contained nitrogen | 9.09% |
| 2008 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
| 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% |
