Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 289.299987792969 | Thousand metric tons of contained nitrogen | NA |
| 2004 | 329.399993896484 | Thousand metric tons of contained nitrogen | 13.86% |
| 2005 | 304.617004394531 | Thousand metric tons of contained nitrogen | -7.52% |
| 2006 | 91.6650009155273 | Thousand metric tons of contained nitrogen | -69.91% |
| 2007 | 100 | Thousand metric tons of contained nitrogen | 9.09% |
| 2008 | 50 | Thousand metric tons of contained nitrogen | -50.00% |
| 2009 | 100 | Thousand metric tons of contained nitrogen | 100.00% |
| 2010 | 200 | Thousand metric tons of contained nitrogen | 100.00% |
| 2011 | 200 | Thousand metric tons of contained nitrogen | 0.00% |
| 2012 | 280 | Thousand metric tons of contained nitrogen | 40.00% |
