Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 44268 | Metric tons | NA |
| 2004 | 53469 | Metric tons | 20.78% |
| 2005 | 38250 | Metric tons | -28.46% |
| 2006 | 67844 | Metric tons | 77.37% |
| 2007 | 14308 | Metric tons | -78.91% |
| 2008 | 20000 | Metric tons | 39.78% |
