Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 560 | Metric tons | NA |
| 2004 | 347 | Metric tons | -38.04% |
| 2005 | 358 | Metric tons | 3.17% |
| 2006 | 329 | Metric tons | -8.10% |
| 2007 | 351 | Metric tons | 6.69% |
| 2008 | 330 | Metric tons | -5.98% |
| 2009 | 370 | Metric tons | 12.12% |
| 2010 | 350 | Metric tons | -5.41% |
| 2011 | 390 | Metric tons | 11.43% |
| 2012 | 380 | Metric tons | -2.56% |
| 2013 | 380 | Metric tons | 0.00% |
