Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2005 | 168 | Thousand metric tons | NA |
| 2006 | 180 | Thousand metric tons | 7.14% |
| 2007 | 265.100006103516 | Thousand metric tons | 47.28% |
| 2008 | 1387.40002441406 | Thousand metric tons | 423.35% |
| 2009 | 1379 | Thousand metric tons | -0.61% |
| 2010 | 3203.19995117188 | Thousand metric tons | 132.28% |
| 2011 | 5678.2998046875 | Thousand metric tons | 77.27% |
| 2012 | 7561.39990234375 | Thousand metric tons | 33.16% |
