Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 9 | Metric tons | NA |
| 2003 | 10 | Metric tons | 11.11% |
| 2004 | 9 | Metric tons | -10.00% |
| 2005 | 19.1499996185303 | Metric tons | 112.78% |
| 2006 | 23.5020008087158 | Metric tons | 22.73% |
| 2007 | 27.753999710083 | Metric tons | 18.09% |
| 2008 | 14.2239999771118 | Metric tons | -48.75% |
| 2009 | 33.8079986572266 | Metric tons | 137.68% |
| 2010 | 41.0040016174316 | Metric tons | 21.28% |
| 2011 | 45.5299987792969 | Metric tons | 11.04% |
| 2012 | 67.4769973754883 | Metric tons | 48.20% |
