Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
Year | Production | Unit of Measure | % Change |
2009 | 4101 | Thousand metric tons | NA |
2010 | 4220 | Thousand metric tons | 2.90% |
2011 | 4253 | Thousand metric tons | 0.78% |
2012 | 4196 | Thousand metric tons | -1.34% |
2013 | 4200 | Thousand metric tons | 0.10% |