Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 79.6999969482422 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 216.199996948242 | Thousand metric tons of contained nitrogen | 171.27% |
| 2005 | 220 | Thousand metric tons of contained nitrogen | 1.76% |
| 2006 | 230 | Thousand metric tons of contained nitrogen | 4.55% |
| 2007 | 300 | Thousand metric tons of contained nitrogen | 30.43% |
| 2008 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
| 2009 | 300 | Thousand metric tons of contained nitrogen | 0.00% |
