Year Number 1960 6911510 1961 7109029 1962 7281192 1963 7458243 1964 7640196 1965 7827726 1966 8019658 1967 8216086 1968 8418152 1969 8629855 1970 8861895 1971 9108878 1972 9365952 1973 9637197 1974 9918979 1975 10209848 1976 10509006 1977 10825496 1978 11163230 1979 11515675 1980 11865246 1981 12212960 1982 12584976 1983 12984131 1984 13342487 1985 13651443 1986 13971682 1987 14310790 1988 14671677 1989 15052447 1990 15446982 1991 15843471 1992 16241548 1993 16643633 1994 17040854 1995 17438874 1996 17844010 1997 18268040 1998 18714708 1999 19176791 2000 19665502 2001 20195577 2002 20758326 2003 21329514 2004 21906444 2005 22496951 2006 23098586 2007 23708320 2008 24326087 2009 24950762 2010 25574719 2011 26205941 2012 26858762 2013 27525597 2014 28196358 2015 28870939 2016 29554303 2017 30222262 2018 30870641 2019 31522290 2020 32180401 2021 32833031 2022 33475870 2023 34121985