Year	constant 2015 US$
1973	503.4969134395165
1974	485.9074191446792
1975	452.28720111870535
1976	445.85488035187643
1977	424.8428389870101
1978	452.421569003614
1979	469.17339268554406
1980	466.76957053358643
1981	509.12039303663124
1982	484.6060026718478
1983	482.3332130223678
1984	480.2383964438988
1985	511.14978567264006
1986	518.7285462522808
1987	525.6662480293177
1988	527.6243416637915
1989	529.5512372224837
1990	554.813746698551
1991	536.4566034016419
1992	543.8474612530061
1993	549.6788035869018
1994	567.2237411063999
1995	577.6553254705287
1996	583.8577228041747
1997	585.8785930297938
1998	598.8682453831478
1999	613.6342769107175
2000	636.2075649636861
2001	654.2255809358709
2002	666.0777682386228
2003	681.7780568833779
2004	722.3315960988772
2005	757.9454954757739
2006	809.5532180028227
2007	860.9477210488308
2008	898.0538133267618
2009	935.09018479577
2010	981.3631875362751
2011	1024.1487029613713
2012	1073.3465890744824
2013	1119.9549000379166
2014	1151.8470783500343
2015	1205.9318368434328
2016	1273.4717875308027
2017	1314.8508285505582
2018	1418.4164811517148
2019	1604.1458578191266
2020	1652.063278949334
2021	1754.0531994007818