Year constant 2015 US$ 2008 18386513033.628025 2009 19215112318.110287 2010 20430650583.696533 2011 17061944188.294718 2012 22656493636.989906 2013 24265037605.58143 2014 40042646225.31646 2015 43312710567.4984 2016 45672820486.65533 2017 46928154972.14666 2018 49156289723.86091 2019 51654200917.99179 2020 53930141193.04425 2021 55752536034.05083