Year Number 1961 172506 1962 180415 1963 184638 1964 190469 1965 198126 1966 205896 1967 214582 1968 218483 1969 227894 1970 237231 1971 236986 1972 235170 1973 235582 1974 238979 1975 241287 1976 248924 1977 250736 1978 249874 1979 251051 1980 251638 1981 254958 1982 254040 1983 253686 1984 254615 1985 254614 1986 254979 1987 246510 1988 238500 1989 235505 1990 233231 1991 230322 1992 221514 1993 213078 1994 218638 1995 224909 1996 208847