Year current US$ 2007 16618380809 2008 20127504748 2009 17057585747.000002 2010 20394443390 2011 26849987689 2012 25441407832 2013 24673076911 2014 26887411371 2015 24757970785 2016 24689661232 2017 29448209320 2018 36023128341 2019 37656863124 2020 39603323141 2021 41415752357 2022 45217937911