Year Number 1960 12325 1961 12530 1962 12771 1963 13029 1964 13340 1965 13715 1966 14232 1967 14710 1968 15050 1969 15393 1970 15758 1971 16172 1972 16626 1973 17079 1974 17505 1975 17921 1976 18347 1977 18767 1978 19277 1979 20081 1980 20921 1981 21602 1982 22312 1983 23057 1984 23832 1985 24650 1986 25510 1987 26323 1988 27061 1989 27808 1990 28512 1991 29139 1992 29789 1993 30476 1994 31147 1995 31784 1996 32439 1997 33252 1998 34186 1999 35168 2000 36278 2001 37490 2002 38723 2003 39993 2004 41306 2005 42603 2006 43885 2007 45150 2008 46301 2009 47347 2010 48436 2011 49686 2012 51054 2013 52481 2014 53969 2015 55319 2016 56640 2017 58249 2018 60120 2019 62153 2020 64406 2021 66729 2022 69139 2023 71781