Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 56.3540000915527 | Thousand metric tons | NA |
| 2004 | 90.4100036621094 | Thousand metric tons | 60.43% |
| 2005 | 286.117004394531 | Thousand metric tons | 216.47% |
| 2006 | 54.3089981079102 | Thousand metric tons | -81.02% |
| 2007 | 273.393005371094 | Thousand metric tons | 403.40% |
