Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 31648 | Metric tons | NA |
| 2004 | 66143 | Metric tons | 109.00% |
| 2005 | 86331 | Metric tons | 30.52% |
| 2006 | 93880 | Metric tons | 8.74% |
| 2007 | 105943 | Metric tons | 12.85% |
| 2008 | 121031 | Metric tons | 14.24% |
| 2009 | 3000 | Metric tons | -97.52% |
| 2010 | 2200 | Metric tons | -26.67% |
| 2011 | 900 | Metric tons | -59.09% |
| 2012 | 800 | Metric tons | -11.11% |
| 2013 | 1050 | Metric tons | 31.25% |
