Year	Percent
1949	2
1950	2
1951	2
1952	2
1953	2
1954	2
1955	2
1956	2
1957	5
1958	5
1959	7
1960	5
1961	3
1962	6
1963	6
1964	6
1965	6
1966	5
1967	6
1968	8
1969	10
1970	10
1971	10
1972	10
1973	10
1974	6
1975	6
1976	6
1977	6
1978	4
1979	11
1980	5
1981	7
1982	6
1983	8
1984	12
1985	13
1986	10
1987	10
1988	10
1989	12
1990	14
1991	14
1992	14
1993	9
1994	8
1995	11
1996	12
1997	15
1998	12
1999	8
2000	14
2001	8
2002	4
2003	6
2004	8
2005	6
2006	5