Year Number 1960 36245 1961 36416 1962 36701 1963 37050 1964 37417 1965 37753 1966 38074 1967 38407 1968 38728 1969 38991 1970 39212 1971 39460 1972 39834 1973 40332 1974 40896 1975 41505 1976 41974 1977 42241 1978 42498 1979 42822 1980 43195 1981 43701 1982 44369 1983 45051 1984 45694 1985 46293 1986 46875 1987 47489 1988 48099 1989 48665 1990 49174 1991 49458 1992 49496 1993 49490 1994 49483 1995 49503 1996 49584 1997 49740 1998 49938 1999 50158 2000 50381 2001 50614 2002 50921 2003 51287 2004 51699 2005 52163 2006 52682 2007 53218 2008 53697 2009 54128 2010 54527 2011 54665 2012 54654 2013 54837 2014 55036 2015 55316 2016 55690 2017 56049 2018 56720 2019 57553 2020 58230 2021 58791 2022 59208 2023 59484