Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 81 | Metric tons | NA |
| 2003 | 79 | Metric tons | -2.47% |
| 2004 | 79 | Metric tons | 0.00% |
| 2005 | 54.0979995727539 | Metric tons | -31.52% |
| 2006 | 11.4630002975464 | Metric tons | -78.81% |
| 2007 | 5.30000019073486 | Metric tons | -53.76% |
| 2008 | 2.04299998283386 | Metric tons | -61.45% |
| 2009 | 1.5 | Metric tons | -26.58% |
| 2010 | 1.20000004768372 | Metric tons | -20.00% |
| 2011 | 4.48600006103516 | Metric tons | 273.83% |
| 2012 | 3.57699990272522 | Metric tons | -20.26% |
