Year	constant 2015 US$
1977	2931.4909605837515
1978	3225.323513215428
1979	2622.683244116566
1980	2965.12471738526
1981	3288.3005919440016
1982	3438.457933372258
1983	3543.775619297076
1984	3709.588351314116
1985	3780.1657887698925
1986	4069.204771568174
1987	4350.7371958902195
1988	4718.2044026623325
1989	4737.585999754479
1990	5029.776161192568
1991	5122.632939347189
1992	5228.7858430818505
1993	5337.399546870615
1994	5337.002354048213
1995	5498.521180364433
1996	5672.075181974976
1997	5803.177312640379
1998	6034.694409268833
1999	6077.21916000036
2000	6251.471177028522
2001	6265.1719532047
2002	6078.271720511081
2003	6447.431432005015
2004	6631.333140561725
2005	6665.105970834139
2006	6968.763248243623
2007	7407.930636254928
2008	7934.646074842494
2009	7841.273187673839
2010	7897.690327127609
2011	7881.5252024328465
2012	7781.532762270599
2013	7711.446037970893
2014	8013.753085242943
2015	7724.0424105737575
2016	7929.805283588161
2017	7370.433116708079
2018	7586.646141000547
2019	7936.304818200302
2020	6566.427356741952
2021	6978.470496782211
2022	7335.194757524879
2023	7648.983290939025