Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 307 | Metric tons | NA |
| 2004 | 356 | Metric tons | 15.96% |
| 2005 | 319 | Metric tons | -10.39% |
| 2006 | 363 | Metric tons | 13.79% |
| 2007 | 459 | Metric tons | 26.45% |
| 2008 | 460 | Metric tons | 0.22% |
| 2009 | 420 | Metric tons | -8.70% |
| 2010 | 420 | Metric tons | 0.00% |
| 2011 | 420 | Metric tons | 0.00% |
| 2012 | 420 | Metric tons | 0.00% |
| 2013 | 400 | Metric tons | -4.76% |
