Year Number 1970 748900 1971 875100 1972 976100 1973 1248900 1974 1508500 1975 1814700 1976 2132100 1977 2497300 1978 2893200 1979 3377500 1980 3826900 1981 4405400 1982 4591500 1983 4531600 1984 4791800 1985 4912300 1986 4990300 1987 5248400 1988 6046900 1989 6659900 1990 7046400 1991 7745500 1992 8477300 1993 9271200 1994 9929400 1995 10779300 1996 11840700 1997 12980700 1998 13331100 1999 15282600 2000 16704341 2001 16373648 2002 17256872 2003 14172367 2004 16995621 2005 17744017 2006 19565884 2007 20671341 2008 21050204 2009 18427473 2010 24859825.1577843 2011 26509929.1424906 2012 29138458.2737476 2013 31729241 2014 33643518.416782 2015 33585397 2016 35370328 2017 38094990 2018 40401515 2019 43050722 2020 7884373 2021 2311712