Year current US$ 1965 278.35244407632695 1966 290.0331743529155 1967 303.71733957402006 1968 339.087517742325 1969 367.7894359272428 1970 402.6781161815656 1971 451.5507332267343 1972 538.2269709890703 1973 719.0091870112797 1974 1286.158377918597 1975 1362.83309395605 1976 1642.1290628931745 1977 1844.5915009655253 1978 1895.2129442669584 1979 2411.5167593756732 1980 3011.781073354857 1981 2977.946778574656 1982 2871.8904473932116 1983 2825.6343075259074 1984 2755.289981365054 1985 2719.905294914977 1986 2667.516023087051 1987 2401.106741602287 1988 2310.5542179021836 1989 2312.978332801601 1990 2908.2413906030833 1991 2085.368626831808 1992 2218.2892048205267 1993 2205.003141978423 1994 2285.60151941858 1995 2468.358703403826 1996 2688.795503886574 1997 2760.0654174885585 1998 2644.03146819218 1999 2817.332826647611 2000 3091.7133268718712 2001 3013.454746580636 2002 2932.633344482977 2003 3205.2625229853734 2004 3706.4759130087687 2005 4350.510776180752 2006 4993.873468775418 2007 5763.882095030688 2008 7032.085696703554 2009 6163.519632578054 2010 7086.154551656779 2011 8365.338556983499 2012 8838.39907272597 2013 8518.95410497194 2014 8403.789855596835 2015 7266.659229289896 2016 7204.573743929837 2017 7380.4056994215225 2018 7607.522628596221 2019 7501.968964194899 2020 6665.2171774033695 2021 7775.55195119201 2022 9116.772782730943 2023 8561.88648477206