Year current US$ 2000 33.541440527372586 2001 34.96696943557863 2002 39.40440642164189 2003 47.99851146216408 2004 62.926942425768736 2005 76.51608245545403 2006 90.96427639956927 2007 114.51899794723808 2008 139.6939489924422 2009 122.36207067951793 2010 137.28659894302868 2011 155.4064379680831 2012 163.0695345651521 2013 178.88734256584445 2014 169.71853987510565 2015 135.9928604754437 2016 133.50368962886776 2017 153.10104684492748 2018 154.24064040191473 2019 159.3045007797211 2020 149.34949941127522 2021 182.21904951295568