Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 3088 | Metric tons | NA |
| 2004 | 4251 | Metric tons | 37.66% |
| 2005 | 3726 | Metric tons | -12.35% |
| 2006 | 1641 | Metric tons | -55.96% |
| 2007 | 1700 | Metric tons | 3.60% |
