Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 17 | Thousand metric tons | NA |
| 2010 | 11.1999998092651 | Thousand metric tons | -34.12% |
| 2011 | 10 | Thousand metric tons | -10.71% |
| 2012 | 16 | Thousand metric tons | 60.00% |
| 2013 | 17 | Thousand metric tons | 6.25% |
