Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
Year | Production | Unit of Measure | % Change |
2003 | 340 | Thousand metric tons | NA |
2004 | 350.399993896484 | Thousand metric tons | 3.06% |
2005 | 351.399993896484 | Thousand metric tons | 0.29% |
2006 | 337.264007568359 | Thousand metric tons | -4.02% |
2007 | 353 | Thousand metric tons | 4.67% |
2008 | 315.5 | Thousand metric tons | -10.62% |
2009 | 271.902008056641 | Thousand metric tons | -13.82% |
2010 | 343.334991455078 | Thousand metric tons | 26.27% |
2011 | 354.028991699219 | Thousand metric tons | 3.11% |
2012 | 326.963012695313 | Thousand metric tons | -7.65% |
2013 | 324 | Thousand metric tons | -0.91% |