Year Number 1970 1771600 1971 1958800 1972 1890900 1973 1923200 1974 2194700 1975 2412200 1976 3055300 1977 3188700 1978 3283900 1979 3600900 1980 3876500 1981 4082100 1982 4133500 1983 4210500 1984 4251100 1985 3859300 1986 4160000 1987 4155300 1988 4291800 1989 4305700 1990 4670900 1991 4109300 1992 4436300 1993 4392300 1994 4490400 1995 4168400 1996 4464600 1997 4462000 1998 4508400 1999 4601000 2000 4776260 2001 4640077 2010 11761536.134861983 2011 14168273.53912652 2012 13737452.860048708 2013 14815345 2014 14719339.159067588 2015 12867667 2016 13753911 2017 15919522.079999998 2018 17823482.468118146 2019 18690732.68588695 2020 8026937.252 2021 11917901.427