Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1450 | Metric tons | NA |
| 2004 | 1480 | Metric tons | 2.07% |
| 2005 | 1470 | Metric tons | -0.68% |
| 2006 | 723 | Metric tons | -50.82% |
| 2007 | 735 | Metric tons | 1.66% |
| 2008 | 777 | Metric tons | 5.71% |
| 2009 | 633 | Metric tons | -18.53% |
| 2010 | 637 | Metric tons | 0.63% |
