Year Total 1960 13840 1961 14120 1962 14050 1963 14690 1964 15860 1965 16040 1966 16690 1967 16990 1968 17570 1969 18500 1970 19870 1971 19530 1972 20120 1973 20380 1974 21210 1975 20980 1976 21740 1977 20900 1978 20940 1979 20560 1980 19900 1981 20830 1982 22570 1983 21470 1984 22640 1985 22770 1986 24810 1987 24190 1988 25470 1989 25220 1990 25310 1991 26080 1992 27250 1993 28300 1994 29500 1995 29420 1996 30270 1997 30400 1998 30290 1999 29220 2000 28170 2001 26850 2002 27450 2003 27840 2004 28390 2005 27850 2006 27430 2007 26380 2008 26970 2009 27010 2010 28830