Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 79085 | Metric tons | NA |
| 2003 | 124410 | Metric tons | 57.31 % |
| 2004 | 118451 | Metric tons | -4.79 % |
| 2005 | 173635 | Metric tons | 46.59 % |
| 2006 | 222101 | Metric tons | 27.91 % |
| 2007 | 192277 | Metric tons | -13.43 % |
| 2008 | 239528 | Metric tons | 24.57 % |
| 2009 | 200000 | Metric tons | -16.50 % |
