Year Number 1960 6261 1961 6761 1962 7275 1963 7804 1964 8348 1965 8913 1966 9525 1967 10229 1968 11022 1969 11889 1970 12837 1971 13860 1972 14951 1973 16109 1974 17319 1975 18557 1976 19811 1977 21073 1978 22323 1979 23555 1980 24780 1981 26019 1982 27309 1983 28647 1984 30006 1985 31376 1986 32826 1987 34363 1988 35910 1989 37445 1990 38959 1991 40463 1992 41960 1993 43434 1994 44876 1995 46281 1996 47067 1997 47233 1998 47362 1999 47476 2000 47593 2001 48829 2002 51195 2003 53592 2004 56003 2005 58398 2006 58718 2007 57020 2008 55375 2009 53732 2010 52106 2011 51344 2012 51422 2013 51472 2014 51536 2015 51591 2016 52153 2017 53251 2018 54305 2019 55337 2020 56310 2021 57212 2022 57663 2023 57689