Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2009 | 65.3150024414063 | Thousand metric tons | NA |
| 2010 | 214.619995117188 | Thousand metric tons | 228.59% |
| 2011 | 148.011993408203 | Thousand metric tons | -31.04% |
| 2012 | 359.348999023438 | Thousand metric tons | 142.78% |
| 2013 | 200 | Thousand metric tons | -44.34% |
