Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 9100 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 9800 | Thousand metric tons of contained nitrogen | 7.69% |
| 2005 | 10000 | Thousand metric tons of contained nitrogen | 2.04% |
| 2006 | 10500 | Thousand metric tons of contained nitrogen | 5.00% |
| 2007 | 10500 | Thousand metric tons of contained nitrogen | 0.00% |
| 2008 | 10425 | Thousand metric tons of contained nitrogen | -0.71% |
| 2009 | 10441 | Thousand metric tons of contained nitrogen | 0.15% |
| 2010 | 10400 | Thousand metric tons of contained nitrogen | -0.39% |
| 2011 | 10400 | Thousand metric tons of contained nitrogen | 0.00% |
| 2012 | 10300 | Thousand metric tons of contained nitrogen | -0.96% |
