Year Number 1960 19084 1961 19632 1962 20292 1963 20996 1964 21616 1965 22042 1966 22225 1967 22176 1968 21990 1969 21831 1970 21814 1971 22059 1972 22590 1973 23305 1974 24108 1975 24921 1976 25724 1977 26531 1978 27291 1979 27975 1980 28593 1981 29128 1982 29527 1983 29809 1984 30079 1985 30348 1986 30538 1987 30649 1988 30760 1989 30884 1990 31106 1991 31640 1992 32475 1993 33588 1994 34679 1995 35697 1996 36646 1997 37423 1998 38202 1999 38904 2000 39614 2001 40716 2002 41937 2003 43206 2004 44449 2005 45593 2006 46369 2007 46850 2008 47282 2009 47608 2010 47704 2011 47966 2012 48587 2013 49419 2014 50611 2015 52026 2016 53262 2017 54461 2018 55783 2019 57202 2020 58486 2021 59381 2022 60285 2023 61445