Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 147 | Thousand metric tons | NA |
| 2010 | 174 | Thousand metric tons | 18.37% |
| 2011 | 340 | Thousand metric tons | 95.40% |
| 2012 | 400 | Thousand metric tons | 17.65% |
| 2013 | 450 | Thousand metric tons | 12.50% |
