Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 53 | Thousand metric tons | NA |
| 2004 | 34 | Thousand metric tons | -35.85% |
| 2005 | 44 | Thousand metric tons | 29.41% |
| 2006 | 52 | Thousand metric tons | 18.18% |
| 2007 | 50 | Thousand metric tons | -3.85% |
| 2008 | 50 | Thousand metric tons | 0.00% |
| 2009 | 50 | Thousand metric tons | 0.00% |
| 2010 | 50 | Thousand metric tons | 0.00% |
| 2011 | 50 | Thousand metric tons | 0.00% |
| 2012 | 50 | Thousand metric tons | 0.00% |
