Year Number 1960 4824 1961 4873 1962 4924 1963 4977 1964 5033 1965 5108 1966 5195 1967 5295 1968 5404 1969 5515 1970 5755 1971 6175 1972 6664 1973 7168 1974 7701 1975 8247 1976 8794 1977 9346 1978 9890 1979 10448 1980 11054 1981 11704 1982 12384 1983 13090 1984 13815 1985 14559 1986 15312 1987 16070 1988 16823 1989 17610 1990 18572 1991 19687 1992 20822 1993 21959 1994 23093 1995 24219 1996 25344 1997 26453 1998 27548 1999 28628 2000 29671 2001 30720 2002 31813 2003 32928 2004 34074 2005 35254 2006 36455 2007 37677 2008 38909 2009 40120 2010 41273 2011 42346 2012 43382 2013 44433 2014 45471 2015 46470 2016 47432 2017 48348 2018 49225 2019 50063 2020 50875 2021 51368 2022 51580 2023 51811