Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 2356.5 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 2114 | Thousand metric tons of contained nitrogen | -10.29% |
| 2005 | 2114 | Thousand metric tons of contained nitrogen | 0.00% |
| 2006 | 2200 | Thousand metric tons of contained nitrogen | 4.07% |
| 2007 | 2250 | Thousand metric tons of contained nitrogen | 2.27% |
| 2008 | 2300 | Thousand metric tons of contained nitrogen | 2.22% |
| 2009 | 2350 | Thousand metric tons of contained nitrogen | 2.17% |
| 2010 | 2400 | Thousand metric tons of contained nitrogen | 2.13% |
| 2011 | 2450 | Thousand metric tons of contained nitrogen | 2.08% |
| 2012 | 2500 | Thousand metric tons of contained nitrogen | 2.04% |
