Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 31500 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 34770 | Thousand metric tons of contained nitrogen | 10.38 % |
| 2005 | 37850 | Thousand metric tons of contained nitrogen | 8.86 % |
| 2006 | 40660 | Thousand metric tons of contained nitrogen | 7.42 % |
| 2007 | 42480 | Thousand metric tons of contained nitrogen | 4.48 % |
| 2008 | 41140 | Thousand metric tons of contained nitrogen | -3.15 % |
| 2009 | 42290 | Thousand metric tons of contained nitrogen | 2.80 % |
