Year	current US$
1971	187.63381632310444
1972	224.46294118262338
1973	312.77928984482065
1974	362.2670179084401
1975	394.69896652889565
1976	384.59808881719516
1977	451.91704605083476
1978	585.70216656345
1979	774.7952647393251
1980	909.172330697307
1981	975.1689028933826
1982	870.4464861352432
1983	917.105950941284
1984	886.741536027538
1985	776.6720186401584
1986	943.9068873094636
1987	1225.0477116357454
1988	1624.3306909017324
1989	1830.0337276002615
1990	2381.512243175112
1991	2483.71278163843
1992	2569.602891806968
1993	2632.0528818376733
1994	2269.0289826554927
1995	2562.0243866420665
1996	2457.6110080649664
1997	2592.8113170615998
1998	2596.094509825022
1999	2693.4223569069222
2000	2727.6904049660366
2001	2693.915347355599
2002	2273.5082040572156
2003	2866.892886097972
2004	3261.022010502532
2005	3822.440855460974
2006	3742.4160818873866
2007	3989.377658463876
2008	3937.9634696239564
2009	3789.6768893569147
2010	4531.81274325636
2011	5653.868664168896
2012	5226.034998077755
2013	5124.279173304204
2014	5360.085057972257
2015	4548.211465813512
2016	4524.218051665862
2017	4768.263967174749
2018	4821.07067555365
2019	4923.831542912036
2020	4563.263687988032
2021	5061.469176818278