Year constant 2010 US$ 2006 5066.80562052808 2007 5656.69830043079 2008 6276.54935584423 2009 5370.80800256535 2010 5467.98847575976 2011 5487.54267310623 2012 5268.8160922396 2013 5347.29125990342 2014 5494.83109114777 2015 5613.96325975487 2016 5913.5968533117 2017 6145.61558978016 2018 6421.25760102896