Year	current US$
1970	633.9892277062148
1971	771.9656907285429
1972	892.8991994280902
1973	1172.829197481635
1974	3611.433642663666
1975	4358.568846685945
1976	5868.3472208730855
1977	6296.303325208107
1978	6631.886496434301
1979	6069.3443800462655
1980	9693.929730427126
1981	11550.567096823523
1982	11111.864000437097
1983	9439.342013335156
1984	8197.474449564803
1985	7281.832785793483
1986	5926.197755854603
1987	5514.320456168243
1988	5580.229353995765
1989	5617.688633817405
1990	5959.889151832458
1991	6490.885836133195
1992	6602.06847363169
1993	6195.523276813482
1994	5991.888798076366
1995	6192.26530404799
1996	6400.230310260851
1997	6653.041682017398
1998	5865.093176795451
1999	6360.78988519462
2000	6907.058622500684
2001	6731.234777121261
2002	6913.370710645807
2003	7371.542731673705
2004	8354.622426648759
2005	10265.561122169665
2006	11386.352316882212
2007	12305.984758038465
2008	14403.831416613877
2009	12407.276251262429
2010	14642.577300016263
2011	17380.872046493005
2012	18596.862216364476
2013	18517.14806745513
2014	18648.263504138107
2015	16175.073074752438
2016	16043.714200468814
2017	16633.878002110192
2018	19156.953809860595
2019	18613.738349544656
2020	16512.389169045222