Year Number 1961 4100 1962 4173 1963 5226 1964 5230 1965 5235 1966 5245 1967 5252 1968 6100 1969 7000 1970 6810 1971 7212 1972 7611 1973 8367 1974 9385 1975 10410 1976 10442 1977 10616 1978 10820 1979 10962 1980 10533 1981 10208 1982 9832 1983 9374 1984 8670 1985 13200 1986 17700 1987 22200 1988 26700 1989 31200 1990 35750 1991 40250 1992 42300 1993 44400 1994 46400 1995 48500 1996 50500 1997 52600 1998 54700 1999 56800 2000 58800 2001 60900 2002 62952