Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 65813 | Metric tons | NA |
| 2004 | 52483 | Metric tons | -20.25% |
| 2005 | 20564 | Metric tons | -60.82% |
| 2006 | 24529 | Metric tons | 19.28% |
| 2007 | 28000 | Metric tons | 14.15% |
| 2008 | 26000 | Metric tons | -7.14% |
| 2009 | 40792 | Metric tons | 56.89% |
| 2010 | 121800 | Metric tons | 198.59% |
| 2011 | 114100 | Metric tons | -6.32% |
| 2012 | 110000 | Metric tons | -3.59% |
| 2013 | 105000 | Metric tons | -4.55% |
