Year Number 1960 21386083 1961 22203076 1962 22912921 1963 23531323 1964 24013031 1965 24383943 1966 24787915 1967 25236621 1968 25611240 1969 25872156 1970 26047057 1971 26186509 1972 26321053 1973 26451660 1974 26563338 1975 26642452 1976 26733894 1977 26863637 1978 26987375 1979 27141774 1980 27365007 1981 27632344 1982 27940650 1983 28258207 1984 28613646 1985 29024474 1986 29441363 1987 29848217 1988 30222827 1989 30489791 1990 30715792 1991 30877535 1992 30984189 1993 31019501 1994 30924739 1995 30732041 1996 30527185 1997 30249227 1998 29857782 1999 29376940 2000 28894763 2001 28384761 2002 27855239 2003 27346464 2004 26888608 2005 26485749 2006 26151905 2007 25873232 2008 25772102 2009 25762685 2010 25838268 2011 25948095 2012 26059662 2013 26252211 2014 26511111 2015 26824273 2016 27148240 2017 27474107 2018 27818878 2019 28150054 2020 28405113 2021 28634327 2022 28440118 2023 28412244