Year	constant 2011 international $
1990	18898.5866441851
1991	17205.6737696574
1992	16289.4865912065
1993	16792.6340914408
1994	17707.734508302
1995	18431.0451867231
1996	19091.0675739613
1997	20094.4571077514
1998	20800.0059679542
1999	21881.4361908644
2000	22723.3270446698
2001	23356.7055188022
2002	24222.7057674997
2003	24896.119087735
2004	25962.9085086601
2005	26955.4759051744
2006	28389.3382006689
2007	30190.723646843
2008	31137.7763671714
2009	28451.5455225073
2010	28678.3726303687
2011	28804.7015194266
2012	27976.9163065514
2013	27622.6855482922
2014	28409.7555968679
2015	29042.7252330979
2016	29911.8786527953
2017	31351.3042437041
2018	32742.5146464049