Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 900 | Thousand metric tons | NA |
| 2004 | 900 | Thousand metric tons | 0.00% |
| 2005 | 11000 | Thousand metric tons | 1,122.22% |
| 2006 | 12000 | Thousand metric tons | 9.09% |
| 2007 | 12000 | Thousand metric tons | 0.00% |
| 2008 | 13000 | Thousand metric tons | 8.33% |
| 2009 | 13000 | Thousand metric tons | 0.00% |
| 2010 | 14000 | Thousand metric tons | 7.69% |
| 2011 | 15000 | Thousand metric tons | 7.14% |
| 2012 | 15000 | Thousand metric tons | 0.00% |
| 2013 | 16000 | Thousand metric tons | 6.67% |
