Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 870000 | Metric tons | NA |
| 2004 | 1490000 | Metric tons | 71.26% |
| 2005 | 1270000 | Metric tons | -14.77% |
| 2006 | 1540000 | Metric tons | 21.26% |
| 2007 | 1270000 | Metric tons | -17.53% |
| 2008 | 791000 | Metric tons | -37.72% |
| 2009 | 410000 | Metric tons | -48.17% |
