Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 331 | Metric tons | NA |
| 2004 | 260 | Metric tons | -21.45% |
| 2005 | 153 | Metric tons | -41.15% |
| 2006 | 125 | Metric tons | -18.30% |
| 2007 | 269 | Metric tons | 115.20% |
| 2008 | 178 | Metric tons | -33.83% |
| 2009 | 249 | Metric tons | 39.89% |
| 2010 | 300 | Metric tons | 20.48% |
| 2011 | 309 | Metric tons | 3.00% |
| 2012 | 310 | Metric tons | 0.32% |
| 2013 | 290 | Metric tons | -6.45% |
