Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 1150 | Thousand metric tons | NA |
| 2004 | 1210 | Thousand metric tons | 5.22% |
| 2005 | 1148.35803222656 | Thousand metric tons | -5.09% |
