Year current US$ 2000 38.556238184712655 2001 39.708149332355404 2002 44.27127004553723 2003 50.556070562628484 2004 56.867322484034126 2005 65.31063584667208 2006 74.90199271073121 2007 89.57632929681475 2008 117.05308848835098 2009 139.07967456167003 2010 161.02469612096667 2011 201.14562322283697 2012 234.52350243297485 2013 265.06314014490755 2014 288.73813876075695 2015 308.6512277062107 2016 313.91661692495035 2017 344.2002206369173 2018 390.15299672812944 2019 416.35885754716026 2020 447.99770466508045 2021 515.7247290231008