Year Number 1960 15882942 1961 15974602 1962 16122316 1963 16293427 1964 16444801 1965 16567643 1966 16665879 1967 16737840 1968 16791120 1969 16832243 1970 16869174 1971 16905371 1972 16962781 1973 17044971 1974 17132173 1975 17234148 1976 17342926 1977 17450553 1978 17564700 1979 17699322 1980 17907967 1981 18137873 1982 18339009 1983 18551176 1984 18750418 1985 18881207 1986 18966530 1987 19056124 1988 19138160 1989 19217086 1990 19289088 1991 19404657 1992 19483936 1993 19471194 1994 19443834 1995 19390391 1996 19330443 1997 19282008 1998 19229773 1999 19169472 2000 19109256 2001 19055902 2002 19017858 2003 19043620 2004 19111233 2005 19124658 2006 19102478 2007 19148415 2008 19236343 2009 19274366 2010 19286658 2011 19246702 2012 19211108 2013 19363208 2014 19470483 2015 19407371 2016 19362338 2017 19340502 2018 19315832 2019 19078096 2020 18961785 2021 18848949 2022 18758773 2023 18667132