Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 575.637023925781 | Thousand metric tons | NA |
| 2004 | 1196.80895996094 | Thousand metric tons | 107.91% |
| 2005 | 1314.11499023438 | Thousand metric tons | 9.80% |
