Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 123000 | Metric tons | NA |
| 2010 | 132000 | Metric tons | 7.32% |
| 2011 | 117000 | Metric tons | -11.36% |
| 2012 | 128000 | Metric tons | 9.40% |
| 2013 | 117000 | Metric tons | -8.59% |
