Year current US$ 1970 528772.586805449 1971 527041.444647705 1972 540018.07296282 1973 1035582.07920015 1974 1024776.25057091 1975 1437717.7653276 1976 1096959.3872237 1977 1248453.96881167 1978 1527881.08830879 1979 2364206.90221548 1980 2610803.46680607 1981 2153167.67386367 1982 3142909.12507402 1983 1888561.70533274 1984 1416113.85812255 1985 1197345.26353765 1986 1062813.88178228 1987 2158784.96685282 1988 2132254.49805884 1989 2400182.0958369 1990 3147308.97598246 1991 3210310.03566222 1992 3311619.51953518 1993 3276240.86513114 1994 3065982.56746469 1995 3988740.01589025 1996 3490222.89809923 1997 3443298.24737283 1998 3022844.07736749 1999 2748411.12214923 2000 2281448.46102791 2001 2381680.68447169 2002 2643521.57645875 2003 2716957.64676386 2004 2575295.32962177 2005 2724079.46136801 2006 2838685.27596952 2007 3644203.17188754 2008 4088480.18436012 2009 3948375.41794042 2010 6823086.35448978 2011 6171098.92174176 2012 6042526.46267953 2013 7383181.5174018 2014 8234144.4447445 2015 7230863.76562175 2016 8630946.20587157 2017 8135506.60231354 2018 6747383.64085985 2019 5938162.42691638 2020 7114715.62379336 2021 6007089.59267243