Year	constant 2015 US$
1970	15516.006321787512
1971	15977.011488894886
1972	16580.998328806076
1973	17273.585931635418
1974	17118.578554932898
1975	17036.15584323756
1976	17929.566732302243
1977	18552.44529226343
1978	19339.64831052415
1979	19836.850765464616
1980	19624.191049493656
1981	19235.90983927565
1982	19163.80891573071
1983	19655.875561908186
1984	20271.144672377097
1985	20831.806495465313
1986	21969.849838841554
1987	22398.47135780178
1988	23295.7461141167
1989	23892.99903511062
1990	25004.46891108485
1991	25764.6322905445
1992	26187.686471968307
1993	25659.232943486913
1994	26190.782264425976
1995	26558.37052730369
1996	26670.93013463865
1997	26909.93980705435
1998	27482.696805598876
1999	27967.808394582713
2000	28325.300299879913
2001	28684.585465273765
2002	28542.59426790631
2003	28458.5791183038
2004	29381.659386423264
2005	29485.17565805656
2006	30884.197217679164
2007	31796.50134151892
2008	31585.439042087844
2009	30324.99308555853
2010	31499.935470165135
2011	33341.331328535845
2012	33220.42320297107
2013	33314.8445866877
2014	34019.012469487156
2015	34656.44190574965
2016	35486.15342196272
2017	36142.68456382204
2018	36523.107785060834
2019	36757.899470020086
2020	34992.27365800727
2021	35701.858221998475