Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2004 | 37 | Thousand metric tons | NA |
| 2005 | 38 | Thousand metric tons | 2.70% |
| 2006 | 44 | Thousand metric tons | 15.79% |
| 2007 | 45 | Thousand metric tons | 2.27% |
| 2008 | 50 | Thousand metric tons | 11.11% |
| 2009 | 200 | Thousand metric tons | 300.00% |
| 2010 | 200 | Thousand metric tons | 0.00% |
| 2011 | 100 | Thousand metric tons | -50.00% |
| 2012 | 100 | Thousand metric tons | 0.00% |
| 2013 | 100 | Thousand metric tons | 0.00% |
