Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 145060 | Metric tons | NA |
| 2004 | 55859 | Metric tons | -61.49% |
| 2005 | 139833 | Metric tons | 150.33% |
| 2006 | 32878 | Metric tons | -76.49% |
| 2007 | 45778 | Metric tons | 39.24% |
| 2008 | 44067 | Metric tons | -3.74% |
| 2009 | 40340 | Metric tons | -8.46% |
| 2010 | 54311 | Metric tons | 34.63% |
| 2011 | 120417 | Metric tons | 121.72% |
| 2012 | 120566 | Metric tons | 0.12% |
| 2013 | 174786 | Metric tons | 44.97% |
