Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 5.69999980926514 | Thousand metric tons | NA |
| 2004 | 2.03999996185303 | Thousand metric tons | -64.21% |
| 2005 | 4.7350001335144 | Thousand metric tons | 132.11% |
| 2006 | 91.8059997558594 | Thousand metric tons | 1,838.88% |
| 2007 | 156.785003662109 | Thousand metric tons | 70.78% |
| 2008 | 295.175994873047 | Thousand metric tons | 88.27% |
| 2009 | 280 | Thousand metric tons | -5.14% |
