Year Number 1960 35001 1961 35549 1962 35973 1963 36409 1964 36872 1965 37317 1966 37728 1967 38094 1968 38396 1969 38669 1970 38912 1971 39168 1972 39513 1973 39937 1974 40422 1975 40958 1976 41336 1977 41491 1978 41633 1979 41835 1980 42083 1981 42531 1982 43245 1983 44051 1984 44829 1985 45571 1986 46251 1987 46834 1988 47388 1989 47909 1990 48372 1991 48580 1992 48504 1993 48393 1994 48290 1995 48200 1996 48228 1997 48401 1998 48606 1999 48797 2000 48998 2001 49272 2002 49641 2003 50054 2004 50488 2005 50978 2006 51552 2007 52173 2008 52768 2009 53309 2010 53820 2011 54033 2012 54053 2013 54307 2014 54594 2015 54958 2016 55385 2017 55862 2018 56815 2019 57925 2020 58803 2021 59516 2022 60003 2023 60319