Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 766 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 767 | Thousand metric tons of contained nitrogen | 0.13% |
| 2005 | 774 | Thousand metric tons of contained nitrogen | 0.91% |
| 2006 | 815 | Thousand metric tons of contained nitrogen | 5.30% |
| 2007 | 830 | Thousand metric tons of contained nitrogen | 1.84% |
| 2008 | 743.400024414063 | Thousand metric tons of contained nitrogen | -10.43% |
| 2009 | 828.599975585938 | Thousand metric tons of contained nitrogen | 11.46% |
| 2010 | 835.900024414063 | Thousand metric tons of contained nitrogen | 0.88% |
| 2011 | 803.900024414063 | Thousand metric tons of contained nitrogen | -3.83% |
| 2012 | 815.200012207031 | Thousand metric tons of contained nitrogen | 1.41% |
