Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 24.125 | Thousand metric tons | NA |
| 2010 | 6.19399976730347 | Thousand metric tons | -74.33% |
| 2011 | 24.6389999389648 | Thousand metric tons | 297.79% |
| 2012 | 9.97999954223633 | Thousand metric tons | -59.50% |
| 2013 | 10 | Thousand metric tons | 0.20% |
