Year	current US$
1971	2430.216704676663
1972	2877.520276682713
1973	3781.197570549387
1974	3967.972022806164
1975	3431.0220036566116
1976	3552.6033002073623
1977	3969.7054674312226
1978	4756.659726744554
1979	5372.932735564329
1980	6063.773657957949
1981	6356.520183075523
1982	6182.759770549571
1983	6105.863302610602
1984	5295.79336308128
1985	5903.865663004065
1986	7462.559640985183
1987	9818.131048395615
1988	11164.038571083967
1989	10759.449897491786
1990	10966.62043455718
1991	9441.384921830677
1992	9109.103330188917
1993	10110.217733809388
1994	11943.264448967017
1995	13729.905051820113
1996	14579.048900256512
1997	13802.093918711977
1998	11834.418811940628
1999	12131.406202797763
2000	10713.477088459264
2001	11055.345656110681
2002	13539.773575912524
2003	17792.4675275219
2004	20395.30592340658
2005	21955.78663459977
2006	20882.772717638436
2007	25405.150743527156
2008	23867.851209317105
2009	22466.3564739316
2010	26700.63662278668
2011	30794.530891934533
2012	32281.409692634465
2013	35087.22424483961
2014	36328.597632335885
2015	31702.730372189442
2016	33030.98367621858
2017	35289.26093932878
2018	35119.88385603722
2019	35420.77532548502
2020	34536.81715918451
2021	40518.24553515896