Year current US$ 1995 730.712890625 1996 678.98583984375 1997 778.714294433594 1998 653.420288085938 1999 488.977264404297 2000 491.862457275391 2001 615.065307617188 2002 696.734802246094 2003 828.95849609375 2004 1102.45275878906 2005 1503.66528320313 2006 1893.58850097656 2007 2583.10986328125 2008 3273.69970703125 2009 2046.994140625 2010 2467.41235351563 2011 2949.33349609375 2012 3400.23022460938 2013 3523.06079101563 2014 2651.28735351563 2015 1935.65661621094 2016 1910.05041503906 2017 2340.39501953125 2018 2723.015625 2019 3234.33544921875 2020 3317.01782226563 2021 3961.404296875