Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 70 | Thousand metric tons | NA |
| 2010 | 130 | Thousand metric tons | 85.71% |
| 2011 | 180 | Thousand metric tons | 38.46% |
| 2012 | 240 | Thousand metric tons | 33.33% |
| 2013 | 290 | Thousand metric tons | 20.83% |
