Year Number 1960 14127 1961 14607 1962 15067 1963 15507 1964 15855 1965 16183 1966 16500 1967 16791 1968 17162 1969 17566 1970 17952 1971 18325 1972 18688 1973 19060 1974 19481 1975 19941 1976 20442 1977 20963 1978 21500 1979 22028 1980 22482 1981 22843 1982 23231 1983 23670 1984 24067 1985 24501 1986 25077 1987 25650 1988 26132 1989 26594 1990 27086 1991 27621 1992 28187 1993 28759 1994 29361 1995 30028 1996 30636 1997 31190 1998 31679 1999 32077 2000 32512 2001 33022 2002 33519 2003 33928 2004 34327 2005 34776 2006 35297 2007 35981 2008 36764 2009 37599 2010 38598 2011 39723 2012 40969 2013 42331 2014 43770 2015 45283 2016 46732 2017 48190 2018 49840 2019 51589 2020 53400 2021 55601 2022 58542 2023 61947