Year constant 2010 US$ 2006 2977.67388413766 2007 3233.75967436359 2008 3255.681082898 2009 3252.25442366454 2010 3333.82215517622 2011 3489.68764915781 2012 3589.60418440803 2013 3648.21270468325 2014 3688.62092775151 2015 3864.79400865586 2016 3980.21023342221 2017 4174.23263528045 2018 4275.91131905142