Year	constant 2015 US$
1972	2548.0759400553784
1973	2409.368411216598
1974	2570.8649776020884
1975	2500.206931188745
1976	2471.0889780219804
1977	2584.317724441762
1978	2845.5950530028435
1979	2430.6140231023223
1980	3127.7171146660335
1981	3568.220602578046
1982	3632.096129993613
1983	3739.6437176358254
1984	3681.8622277312356
1985	3718.18368162609
1986	3208.3973771772035
1987	2660.3194034108396
1988	2509.3333667544393
1989	2536.8161325490664
1990	2456.2129875037976
1991	2330.8843081041223
1992	2224.5611819944106
1993	1999.0996084593303
1994	1971.7605198061176
1995	1912.4173797083672
1996	1870.8391650444012
1997	1868.810334509519
1998	1962.758806970862
1999	1923.3778876597873
2000	2266.206723192667
2001	2234.126856118694
2002	2251.952350415471
2003	2423.344668117084
2004	2543.4353480865248
2005	2770.6833351446558
2006	2958.416906466387
2007	3119.4391373480134
2008	3288.3286413208484
2009	2950.718488189176
2010	3291.722265589925
2011	3378.923060650045
2012	3611.343378592116
2013	3570.8980347722822
2014	3474.3899774336705
2015	3359.117637262293
2016	3446.8317203451365
2017	3434.76800981449
2018	3364.8265186052977
2019	3307.6097539933307
2020	3051.0673587107035
2021	3122.585147002007