Year current US$ 1995 35000000 1996 40000000 1997 38000000 1998 39000000 1999 42000000 2000 41000000 2001 39000000 2002 45000000 2003 54000000 2004 69000000 2005 73000000 2006 87000000 2007 102000000 2008 111000000 2009 115000000 2010 123000000 2011 134000000 2012 148000000 2013 136000000 2014 147000000 2015 142000000 2016 148000000 2017 166000000 2018 192000000 2019 206000000 2020 23000000