Year	current US$
1998	780.6757685488265
1999	606.4785774784928
2000	653.5089928135471
2001	694.3441371113745
2002	735.4952379795551
2003	865.4680279270401
2004	1146.5455577215112
2005	1441.3367400694945
2006	1774.220478202001
2007	2296.383425661693
2008	2882.5801867438804
2009	2433.037237915617
2010	2713.940098635855
2011	3350.545342547374
2012	3765.0706750428144
2013	3904.2953019426154
2014	4038.9866622896507
2015	3333.0612510476267
2016	3259.6032834968696
2017	3507.47907705378
2018	3863.8884082218697
2019	3802.1266050094337
2020	3499.623053271429
2021	4084.9705741152884