Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 110510.5234375 | Thousand metric tons | NA |
| 2004 | 112717.6640625 | Thousand metric tons | 2.00% |
| 2005 | 112471.375 | Thousand metric tons | -0.22% |
| 2006 | 116266 | Thousand metric tons | 3.37% |
| 2007 | 120203 | Thousand metric tons | 3.39% |
