Year Number 1960 44400 1961 45500 1962 46600 1963 47700 1964 48900 1965 50100 1966 51000 1967 52000 1968 53000 1969 54000 1970 55000 1971 54600 1972 54200 1973 53800 1974 53400 1975 53000 1976 53200 1977 53400 1978 53600 1979 53800 1980 54670 1981 55050 1982 55449 1983 55930 1984 56423 1985 56898 1986 57382 1987 57849 1988 58347 1989 58841 1990 59326 1991 59021 1992 58595 1993 58910 1994 59320 1995 59746 1996 60129 1997 60497 1998 60943 1999 61285 2000 61833 2001 62504 2002 62912 2003 63325 2004 63740 2005 64154 2006 64523 2007 64888 2008 65273 2009 65636 2010 65124 2011 64564 2012 64798 2013 65001 2014 65138 2015 65237 2016 64554 2017 63873 2018 63918 2019 63911 2020 63893 2021 63764 2022 63595 2023 63489