Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 35.7929992675781 | Thousand metric tons | NA |
| 2010 | 141.839996337891 | Thousand metric tons | 296.28% |
| 2011 | 10.7910003662109 | Thousand metric tons | -92.39% |
| 2012 | 26.3150005340576 | Thousand metric tons | 143.86% |
| 2013 | 26 | Thousand metric tons | -1.20% |
