Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 114870 | Metric tons | NA |
| 2004 | 101896 | Metric tons | -11.29% |
| 2005 | 64827 | Metric tons | -36.38% |
| 2006 | 9834 | Metric tons | -84.83% |
| 2007 | 9800 | Metric tons | -0.35% |
| 2008 | 32410 | Metric tons | 230.71% |
| 2009 | 33421 | Metric tons | 3.12% |
| 2010 | 870 | Metric tons | -97.40% |
| 2011 | 51221 | Metric tons | 5,787.47% |
| 2012 | 51000 | Metric tons | -0.43% |
| 2013 | 50000 | Metric tons | -1.96% |
