Year Number 1960 28965 1961 29413 1962 29798 1963 30191 1964 30666 1965 31220 1966 31777 1967 32353 1968 32949 1969 33569 1970 34003 1971 34148 1972 34142 1973 34061 1974 33974 1975 33917 1976 33923 1977 34011 1978 34135 1979 34294 1980 34456 1981 34568 1982 34664 1983 34772 1984 34682 1985 34380 1986 34071 1987 33755 1988 33434 1989 33120 1990 32834 1991 32916 1992 33487 1993 34212 1994 34974 1995 35779 1996 36627 1997 37483 1998 38293 1999 39039 2000 39748 2001 40383 2002 40894 2003 41329 2004 41753 2005 42209 2006 42715 2007 43270 2008 43883 2009 44522 2010 45097 2011 45588 2012 46022 2013 46401 2014 46748 2015 47087 2016 47388 2017 47658 2018 47910 2019 48156 2020 48428 2021 48709 2022 48981 2023 49246