Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 44 | Metric tons | NA |
| 2003 | 45 | Metric tons | 2.27% |
| 2004 | 27 | Metric tons | -40.00% |
| 2005 | 30.0030002593994 | Metric tons | 11.12% |
| 2006 | 31.306999206543 | Metric tons | 4.35% |
| 2007 | 30 | Metric tons | -4.17% |
| 2008 | 33 | Metric tons | 10.00% |
| 2009 | 11 | Metric tons | -66.67% |
| 2010 | 10 | Metric tons | -9.09% |
| 2011 | 9 | Metric tons | -10.00% |
| 2012 | 9 | Metric tons | 0.00% |
