Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 11290 | Metric tons | NA |
| 2004 | 6316 | Metric tons | -44.06% |
| 2005 | 15671 | Metric tons | 148.12% |
| 2006 | 23773 | Metric tons | 51.70% |
| 2007 | 24000 | Metric tons | 0.95% |
| 2008 | 25000 | Metric tons | 4.17% |
| 2009 | 33300 | Metric tons | 33.20% |
| 2010 | 42100 | Metric tons | 26.43% |
| 2011 | 44500 | Metric tons | 5.70% |
| 2012 | 16520 | Metric tons | -62.88% |
| 2013 | 26077 | Metric tons | 57.85% |
