Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 23.1909999847412 | Thousand metric tons | NA |
| 2010 | 34.1520004272461 | Thousand metric tons | 47.26% |
| 2011 | 1.26300001144409 | Thousand metric tons | -96.30% |
| 2012 | 33.2700004577637 | Thousand metric tons | 2,534.20% |
| 2013 | 34 | Thousand metric tons | 2.19% |
