Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 300 | Metric tons | NA |
| 2003 | 800 | Metric tons | 166.67% |
| 2004 | 3200 | Metric tons | 300.00% |
| 2005 | 4400 | Metric tons | 37.50% |
| 2006 | 3800 | Metric tons | -13.64% |
| 2007 | 8900 | Metric tons | 134.21% |
| 2008 | 11800 | Metric tons | 32.58% |
| 2009 | 9900 | Metric tons | -16.10% |
| 2010 | 8600 | Metric tons | -13.13% |
| 2011 | 4800 | Metric tons | -44.19% |
| 2012 | 3700 | Metric tons | -22.92% |
| 2013 | 3000 | Metric tons | -18.92% |