Year Number 1960 33513 1961 33874 1962 34336 1963 34865 1964 35398 1965 35910 1966 36413 1967 36912 1968 37419 1969 37962 1970 38522 1971 39077 1972 39643 1973 40232 1974 40849 1975 41489 1976 42040 1977 42407 1978 42611 1979 42647 1980 42512 1981 42210 1982 41751 1983 41164 1984 40492 1985 39763 1986 38987 1987 38168 1988 37411 1989 36927 1990 36734 1991 36734 1992 36936 1993 37312 1994 37782 1995 38151 1996 38537 1997 39083 1998 39698 1999 40382 2000 41113 2001 41615 2002 42194 2003 42981 2004 43694 2005 44505 2006 45235 2007 45996 2008 47001 2009 48167 2010 49379 2011 50365 2012 51052 2013 51636 2014 52187 2015 53553 2016 55831 2017 58148 2018 60441 2019 62803 2020 64811 2021 65779 2022 66528 2023 67829