Year Number 1960 11840 1961 11816 1962 11901 1963 12081 1964 12332 1965 12643 1966 13024 1967 13482 1968 13968 1969 14421 1970 14814 1971 15149 1972 15430 1973 15687 1974 15890 1975 15760 1976 15359 1977 14973 1978 14557 1979 14117 1980 13917 1981 14188 1982 14712 1983 15227 1984 15694 1985 16086 1986 16358 1987 16505 1988 16534 1989 16509 1990 16515 1991 16921 1992 17750 1993 18691 1994 19759 1995 20936 1996 22199 1997 23522 1998 24847 1999 26060 2000 27216 2001 28457 2002 29772 2003 31214 2004 32949 2005 35097 2006 37642 2007 40528 2008 43844 2009 47792 2010 52021 2011 55589 2012 58512 2013 61334 2014 64121 2015 66120 2016 67269 2017 68246 2018 68989 2019 69518 2020 69836 2021 69817 2022 69834 2023 70121