Year Number 1960 21022 1961 21577 1962 22118 1963 22647 1964 23186 1965 23742 1966 24304 1967 24872 1968 25446 1969 26025 1970 26607 1971 27118 1972 27732 1973 28137 1974 28658 1975 29334 1976 29945 1977 30630 1978 30865 1979 31153 1980 31465 1981 31885 1982 32111 1983 32108 1984 32338 1985 32641 1986 32885 1987 34354 1988 34470 1989 34620 1990 34750 1991 35174 1992 35309 1993 36035 1994 37034 1995 37677 1996 38347 1997 38728 1998 39342 1999 40062 2000 40339 2001 40294 2002 41486 2003 40933 2004 40663 2005 40744 2006 41489 2007 41587 2008 42403 2009 42438 2010 43487 2011 42194 2012 42453 2013 43102 2014 43671 2015 44575 2016 45099 2017 45576 2018 45934 2019 46256 2020 46598 2021 46958 2022 56766 2023 56834