Year	Percent
1975	7.03
1976	9.25
1977	11.68
1978	12.02
1979	7.36
1980	6.12
1981	5.49
1982	5.6
1983	7
1984	5.77
1985	5.25
1986	4.23
1987	1.99
2001	9.05
2006	13.74
2011	5.57
2020	8.33