Year current US$ 1996 67000000 1997 76000000 2003 58000000 2004 51000000 2005 59000000 2006 69000000 2007 87000000 2008 80199996.9482422 2009 64000000 2010 80000000 2011 86000000 2012 104000000 2013 78000000 2014 110000000 2015 92000000 2016 88000000 2017 128000000 2018 174000000 2019 157000000 2020 53000000