Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 6 | Thousand metric tons | NA |
| 2004 | 6.69999980926514 | Thousand metric tons | 11.67% |
| 2005 | 18.2999992370605 | Thousand metric tons | 173.13% |
| 2006 | 12.6000003814697 | Thousand metric tons | -31.15% |
| 2007 | 13 | Thousand metric tons | 3.17% |
| 2008 | 12 | Thousand metric tons | -7.69% |
| 2009 | 12 | Thousand metric tons | 0.00% |
