Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1115.09997558594 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 1087.69995117188 | Thousand metric tons of contained nitrogen | -2.46 % |
| 2005 | 1020 | Thousand metric tons of contained nitrogen | -6.22 % |
| 2006 | 1020 | Thousand metric tons of contained nitrogen | 0.00 % |
| 2007 | 2000 | Thousand metric tons of contained nitrogen | 96.08 % |
| 2008 | 2000 | Thousand metric tons of contained nitrogen | 0.00 % |
| 2009 | 2000 | Thousand metric tons of contained nitrogen | 0.00 % |
