Year current US$ 1997 4000000 1998 5000000 1999 3000000 2000 4000000 2001 11000000 2002 4000000 2003 7000000 2004 16000000 2005 11000000 2006 36000000 2007 16000000 2008 4000000 2009 32000000 2010 24000000 2011 30000000 2012 41000000 2013 59000000 2014 37000000 2015 22000000 2016 17000000 2017 15000000 2018 16000000 2019 20100000.3814697