Year current US$ 2009 37327286540.30878 2010 40855254689.967316 2011 45905091453.20405 2012 43400588178.07462 2013 42813083292.572754 2014 41266334985.3286 2015 36513874990.325485 2016 35959985010.688774 2017 39267314475.663795 2018 42241335987.236725 2019 40819052486.081764