Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 795 | Metric tons, gross weight | NA |
| 2004 | 1683 | Metric tons, gross weight | 111.70% |
| 2005 | 320 | Metric tons, gross weight | -80.99% |
| 2006 | 894 | Metric tons, gross weight | 179.38% |
| 2007 | 682 | Metric tons, gross weight | -23.71% |
| 2008 | 233 | Metric tons, gross weight | -65.84% |
| 2009 | 25 | Metric tons, gross weight | -89.27% |
| 2010 | 732 | Metric tons, gross weight | 2,828.00% |
| 2011 | 779 | Metric tons, gross weight | 6.42% |
| 2012 | 600 | Metric tons, gross weight | -22.98% |
