Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 30 | Thousand metric tons | NA |
| 2003 | 30 | Thousand metric tons | 0.00% |
| 2004 | 30 | Thousand metric tons | 0.00% |
| 2005 | 30 | Thousand metric tons | 0.00% |
| 2006 | 30 | Thousand metric tons | 0.00% |
| 2007 | 30 | Thousand metric tons | 0.00% |
| 2008 | 468 | Thousand metric tons | 1,460.00% |
| 2009 | 563 | Thousand metric tons | 20.30% |
| 2010 | 587 | Thousand metric tons | 4.26% |
| 2011 | 590 | Thousand metric tons | 0.51% |
| 2012 | 600 | Thousand metric tons | 1.69% |
