Year	constant 2010 US$
1991	369.078584996968
1992	363.781060085954
1993	364.505472024158
1994	348.836268909521
1995	346.043720474718
1996	344.571429512136
1997	340.700053465293
1998	337.261711804568
1999	338.936967616856
2000	332.209131471312
2001	334.966111225505
2002	312.695759955996
2003	308.110854120369
2004	294.803696304321
2005	284.027137386577
2006	284.902740071437
2007	287.311650357055
2008	292.90824783652
2009	314.135006151629
2010	301.715799799573
2011	295.696776378549
2012	297.297782670692
2013	271.053087676232
2014	274.505172662908
2015	267.40296446441
2016	263.789054391173
2017	253.471698831931