Year constant 2010 US$ 1991 336.615942653496 1992 248.499598807814 1993 381.6277045886 1994 274.550412192454 1995 384.7759486466 1996 478.379372782327 1997 474.106690371556 1998 507.862158212104 1999 545.303483789419 2000 557.345012917635 2001 509.320474527807 2002 526.779068430158 2003 534.539780093232 2004 542.307610879964 2005 479.565844222572 2006 444.414452517012 2007 466.688561489463 2008 469.783781605848 2009 478.063106419263 2010 497.321705219022 2011 504.550665884631 2012 488.000841528084 2013 502.961343940336 2014 516.750106645286 2015 490.280328318428 2016 463.504692790089 2017 470.223491702668