Year constant 2015 US$ 2004 535.1404697223516 2005 511.4508125908281 2006 511.4513892938981 2007 522.2605005397942 2008 510.2237049414395 2009 523.9223217673004 2010 523.3134465422715 2011 458.98802271158274 2012 456.966515274297 2013 456.02889952221835 2014 434.5378126164374 2015 451.95140489161975 2016 453.8623347859444 2017 454.72927871070857 2018 514.4915749167877 2019 517.4058227665234 2020 497.0918708707807 2021 526.3437082243237