Year constant 2010 US$ 2006 4299.92382228327 2007 4556.87300899255 2008 4848.9301382474 2009 4732.75340759317 2010 4710.91236327574 2011 4774.2616705643 2012 4807.60421211115 2013 5033.69127082914 2014 5154.82362699422 2015 5388.88908751102 2016 5606.58338024233 2017 5801.31969407821 2018 6024.321015942