Year	current US$
1993	204.15164730328465
1994	223.7401150479564
1995	223.73023386824758
1996	250.74456545356887
1997	246.21943713585765
1998	269.4816728465876
1999	254.10161242175502
2000	252.68771474008685
2001	262.7619793199197
2002	247.86329734711734
2003	280.498610310389
2004	345.66194234183394
2005	338.42784708714805
2006	372.417708357376
2007	398.76406227331444
2008	405.8058997175874
2009	542.2370722441833
2010	451.1624310326086
2011	453.743316567417