Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 7017 | Metric tons | NA |
| 2003 | 3864 | Metric tons | -44.93% |
| 2004 | 1196 | Metric tons | -69.05% |
| 2005 | 2819 | Metric tons | 135.70% |
| 2006 | 1478 | Metric tons | -47.57% |
| 2007 | 2071 | Metric tons | 40.12% |
| 2008 | 1783 | Metric tons | -13.91% |
| 2009 | 13268 | Metric tons | 644.14% |
| 2010 | 18263 | Metric tons | 37.65% |
| 2011 | 14014 | Metric tons | -23.27% |
| 2012 | 6158 | Metric tons | -56.06% |
| 2013 | 6474 | Metric tons | 5.13% |
