Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1124 | Metric tons | NA |
| 2004 | 1293 | Metric tons | 15.04% |
| 2005 | 1403 | Metric tons | 8.51% |
| 2006 | 1585 | Metric tons | 12.97% |
| 2007 | 1726 | Metric tons | 8.90% |
| 2008 | 1813 | Metric tons | 5.04% |
| 2009 | 2150 | Metric tons | 18.59% |
| 2010 | 2500 | Metric tons | 16.28% |
| 2011 | 1000 | Metric tons | -60.00% |
| 2012 | 320 | Metric tons | -68.00% |
| 2013 | 500 | Metric tons | 56.25% |
