Year	Percent
1948	2
1949	2
1950	2
1951	2
1952	2
1953	2
1954	2
1955	2
1956	2
1957	3
1958	3
1959	2
1960	2
1961	2
1962	2
1963	2
1964	3
1965	3
1966	4
1967	3
1968	3
1969	4
1970	4
1971	4
1972	4
1973	5
1974	6
1975	3
1976	2
1977	2
1978	1
1979	2
1980	3
1981	6
1982	5
1983	4
1984	4
1985	4
1986	4
1987	3
1988	4
1989	6
1990	6
1991	7
1992	6
1993	4
1994	4
1995	2
1996	1
1997	1
1998	1
1999	1
2000	3
2001	2
2002	1
2003	0
2004	1
2005	1
2006	2