Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 162000 | Metric tons | NA |
| 2004 | 320000 | Metric tons | 97.53% |
| 2005 | 372000 | Metric tons | 16.25% |
| 2006 | 400000 | Metric tons | 7.53% |
| 2007 | 784000 | Metric tons | 96.00% |
| 2008 | 810000 | Metric tons | 3.32% |
| 2009 | 800000 | Metric tons | -1.23% |
