Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4250 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 4120 | Thousand metric tons of contained nitrogen | -3.06% |
| 2005 | 4400 | Thousand metric tons of contained nitrogen | 6.80% |
| 2006 | 4300 | Thousand metric tons of contained nitrogen | -2.27% |
| 2007 | 4400 | Thousand metric tons of contained nitrogen | 2.33% |
| 2008 | 4500 | Thousand metric tons of contained nitrogen | 2.27% |
| 2009 | 4600 | Thousand metric tons of contained nitrogen | 2.22% |
| 2010 | 4800 | Thousand metric tons of contained nitrogen | 4.35% |
| 2011 | 5000 | Thousand metric tons of contained nitrogen | 4.17% |
| 2012 | 5100 | Thousand metric tons of contained nitrogen | 2.00% |
