Year current US$ 2000 1636.52856445 2001 1559.82128906 2002 1763.69567871 2003 2240.74609375 2004 2760.83081055 2005 3014.10473633 2006 3194.03076172 2007 3815.33642578 2008 4107.01269531 2009 4011.93261719 2010 4975.47070313 2011 5909.14990234 2012 6071.65087891 2013 5843.17382813 2014 6130.99853516 2015 5322.97119141 2016 5453.92480469 2017 5813.61376953 2018 5857.28808594 2019 5545.91064453 2020 5958.765625 2021 7055.36816406