Year Number 1960 11335 1961 11610 1962 11865 1963 12097 1964 12318 1965 12538 1966 12757 1967 12978 1968 13209 1969 13461 1970 13746 1971 14081 1972 14594 1973 15011 1974 15471 1975 16024 1976 16572 1977 17160 1978 17427 1979 17682 1980 17929 1981 18218 1982 18422 1983 18502 1984 18676 1985 18872 1986 19032 1987 19918 1988 20156 1989 20528 1990 20904 1991 21421 1992 21692 1993 22360 1994 23159 1995 23626 1996 24079 1997 24823 1998 25834 1999 26603 2000 27126 2001 27428 2002 28543 2003 28509 2004 28740 2005 29174 2006 30080 2007 30506 2008 31441 2009 31829 2010 33032 2011 32471 2012 33000 2013 33740 2014 34353 2015 35175 2016 35648 2017 36058 2018 36387 2019 36707 2020 36990 2021 37211 2022 44753 2023 44454