Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 150 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 200 | Thousand metric tons of contained nitrogen | 33.33% |
| 2005 | 220 | Thousand metric tons of contained nitrogen | 10.00% |
| 2006 | 250 | Thousand metric tons of contained nitrogen | 13.64% |
| 2007 | 270 | Thousand metric tons of contained nitrogen | 8.00% |
| 2008 | 270 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 270 | Thousand metric tons of contained nitrogen | 0.00% |
| 2010 | 270 | Thousand metric tons of contained nitrogen | 0.00% |
| 2011 | 270 | Thousand metric tons of contained nitrogen | 0.00% |
| 2012 | 280 | Thousand metric tons of contained nitrogen | 3.70% |
