Year Number 1970 3397400 1971 3926200 1972 4054100 1973 4514400 1974 4575000 1975 4691800 1976 5084900 1977 5437100 1978 5686800 1979 5887400 1980 5930100 1981 6220600 1982 6252200 1983 6266800 1984 6254500 1985 6506200 1986 6707800 1987 7213900 1988 7483500 1989 8229500 1990 8603400 1991 7973600 1992 8255700 1993 9152000 1994 9338200 1995 9859000 1996 10468300 1997 12481600 1998 14298900 1999 16209000 2000 17268093 2001 16914823 2002 13295500 2003 10118096 2004 9287315 2005 9662619 2006 10647142 2007 12298456 2008 14352757 2009 14701206 2010 22146864 2011 24866065 2012 26386306.6034666 2013 27503416 2014 27923164 2015 27011762 2016 25859918 2017 26732570 2018 28857994 2019 30339654 2020 9009607.2 2021 10988881.272