Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 731.700012207031 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 1012.09997558594 | Thousand metric tons of contained nitrogen | 38.32% |
| 2005 | 900 | Thousand metric tons of contained nitrogen | -11.08% |
| 2006 | 1160 | Thousand metric tons of contained nitrogen | 28.89% |
| 2007 | 1160 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 1160 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 1160 | Thousand metric tons of contained nitrogen | 0.00% |
| 2010 | 1160 | Thousand metric tons of contained nitrogen | 0.00% |
| 2011 | 1200 | Thousand metric tons of contained nitrogen | 3.45% |
| 2012 | 1200 | Thousand metric tons of contained nitrogen | 0.00% |
