Year	constant 2010 US$
1991	343.647792617141
1992	353.531781765115
1993	358.613547101476
1994	363.377205161225
1995	363.022078686171
1996	370.42820333068
1997	387.224285019805
1998	398.547891104658
1999	414.864493395554
2000	418.340318824593
2001	437.770001944693
2002	448.917899495065
2003	466.28773330932
2004	470.807301724838
2005	466.319158980047
2006	464.601656834357
2007	467.405584636011
2008	474.906068476947
2009	435.194955907069
2010	507.828535906998
2011	530.017644911248
2012	543.303442457425
2013	560.887582779089
2014	571.460279624245
2015	592.060911348227
2016	601.542259746876
2017	620.658121464111
2018	633.731862102821