Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 2.92400002479553 | Thousand metric tons | NA |
| 2010 | 0.589999973773956 | Thousand metric tons | -79.82% |
| 2011 | 4.29099988937378 | Thousand metric tons | 627.29% |
| 2012 | 5.68400001525879 | Thousand metric tons | 32.46% |
| 2013 | 2 | Thousand metric tons | -64.81% |
