Year	constant 2015 US$
1974	43472.233705360864
1975	42167.82688098327
1976	49005.99505705538
1977	52604.308752459365
1978	54378.18829073303
1979	64531.89095234681
1980	58110.13281186782
1981	45105.92141170114
1982	45364.20247907292
1983	44077.333436786445
1984	42863.07905087489
1985	40810.34862862664
1986	38372.61780359441
1987	37843.189850646544
1988	37010.271826252356
1989	35445.47514434223
1990	34722.59169746056
1991	34762.23475418013
1992	35424.54698470345
1993	34621.76832951067
1994	34827.33403815541
1995	35515.843252588296
1996	35690.98458317184
1997	34377.85757766241
1998	33445.12082803999
1999	33739.4937412866
2000	33985.815478012264
2001	34219.31059534495
2002	34857.39319645093
2003	35202.78909127533
2004	34750.57362936031
2005	34290.11077125208
2006	35213.21842543036
2007	34714.54021865744
2008	33526.00263766971
2009	32449.830327073865
2010	32810.5036446723
2011	33577.060427372984
2012	33456.265292304124
2013	32341.88900792418
2014	31155.744105452875
2015	30681.433969865317
2016	29601.09650404938
2017	29695.880824991862
2018	29437.865177968764
2019	30313.4138627573
2020	30401.843825383963
2021	29673.165877063762
2022	28954.064089609736
2023	29132.946854377515