| Year | 2008 | 2009 | 2010 | 2011 | 2012 | 2012 | 2014 | 2015 | 2016 | 2018 | 2018 | 2019 |
| Export volume (US $100 million) | 3636 | 3686 | 385 | 4256 | 4376 | 4538 | 4774 | 5058 | 5268 | 5314 | 5606 | 5994 |