Year current US$ 1968 2519999.98092651 1969 1919999.95708466 1970 2210000.03814697 1971 2430000.0667572 1972 2630000.1144409203 1973 2980000.01907349 1974 3079999.92370605 1975 5400000.09536743 1976 5070000.17166138 1977 4070000.1716613797 1978 5719999.79019165 1979 7550000.19073486 1980 10079999.923706101 1981 13390000.3433228 1982 13260000.2288818 1983 9430000.30517578 1984 9909999.84741211 1985 7679999.82833862 1986 6280000.20980835 1987 8600000.38146973 1988 10579999.923706101 1989 16000000 1990 15720000.2670288 1991 17309999.4659424 1992 18559999.4659424 1993 17819999.6948242 1994 4610000.1335144 1995 16409999.847412098 1996 9590000.15258789 1997 13409999.8474121 1998 13270000.4577637 1999 9930000.30517578 2000 8739999.77111816 2001 5239999.771118159 2002 5550000.19073486 2003 6809999.94277954 2004 7170000.07629395 2005 7809999.94277954 2006 8619999.88555908 2007 9460000.03814697 2008 10819999.6948242 2009 10569999.6948242 2010 10229999.5422363 2011 6539999.96185303 2012 7939013.00430298 2013 11351735.1150513 2014 8338186.26403809 2015 7704967.498779301 2016 7258401.87072754 2017 6530575.27542114 2018 6170131.20651245 2019 7464569.091796881 2020 6958512.78305054 2021 6713455.20019531 2022 6967606.54449463