Year	constant 2010 US$
1991	347.385537943591
1992	324.46221957786
1993	339.313960752181
1994	322.083500225232
1995	323.032121767719
1996	369.280508064146
1997	363.644572983387
1998	316.373276859323
1999	319.282887480204
2000	316.557165947695
2001	334.913086228594
2002	315.847259193131
2003	268.881509692286
2004	303.228780803726
2005	332.755781854976
2006	360.730062745806
2007	386.921588102568
2008	406.486701902403
2009	423.294702569774
2010	438.421314991485
2011	468.072312373546
2012	476.070085023594
2013	501.10825785732
2014	516.385921969514
2015	538.190066178124
2016	547.335064901761
2017	572.242025692727
2018	579.53588516609