Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 35 | Thousand metric tons | NA |
| 2003 | 2 | Thousand metric tons | -94.29% |
| 2004 | 3 | Thousand metric tons | 50.00% |
| 2005 | 11.2679996490479 | Thousand metric tons | 275.60% |
| 2006 | 7.34100008010864 | Thousand metric tons | -34.85% |
| 2007 | 31.0060005187988 | Thousand metric tons | 322.37% |
| 2009 | 5.46299982070923 | Thousand metric tons | -82.38% |
| 2010 | 1.60399997234344 | Thousand metric tons | -70.64% |
| 2011 | 1.1599999666214 | Thousand metric tons | -27.68% |
| 2012 | 1.1599999666214 | Thousand metric tons | 0.00% |
