Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 14 | Metric tons | NA |
| 2003 | 13 | Metric tons | -7.14 % |
| 2004 | 14 | Metric tons | 7.69 % |
| 2005 | 13.5010004043579 | Metric tons | -3.56 % |
| 2006 | 9.10000038146973 | Metric tons | -32.60 % |
| 2007 | 9.02799987792969 | Metric tons | -0.79 % |
| 2008 | 8.23200035095215 | Metric tons | -8.82 % |
| 2009 | 9.5 | Metric tons | 15.40 % |
