Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 24040 | Metric tons | NA |
| 2010 | 23832 | Metric tons | -0.87% |
| 2011 | 38300 | Metric tons | 60.71% |
| 2012 | 30330 | Metric tons | -20.81% |
| 2013 | 56355 | Metric tons | 85.81% |
