Year current US$ 2005 54000000 2006 93000000 2007 109000000 2008 127000000 2009 121000000 2010 150000000 2011 298000000 2012 108000000 2013 170000000 2014 283000000 2015 127000000 2016 60000000 2017 68000000 2018 115000000