Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 196 | Thousand metric tons | NA |
| 2004 | 871 | Thousand metric tons | 344.39% |
| 2005 | 900 | Thousand metric tons | 3.33% |
| 2006 | 900 | Thousand metric tons | 0.00% |
| 2007 | 900 | Thousand metric tons | 0.00% |
| 2008 | 900 | Thousand metric tons | 0.00% |
| 2009 | 124 | Thousand metric tons | -86.22% |
| 2010 | 124 | Thousand metric tons | 0.00% |
| 2011 | 124 | Thousand metric tons | 0.00% |
| 2012 | 87.4810028076172 | Thousand metric tons | -29.45% |
| 2013 | 87.5 | Thousand metric tons | 0.02% |
