Year	Percent
1971	0.4482
1973	3.465
1974	2.081
1975	2.482
1976	1.244
1977	1.843
1978	1.731
1979	1.322
1980	3.415
1981	1.829
1982	3.822
1983	2.559
1984	1.109
1985	1.962
1986	2.482
1987	1.869
1988	2.531
1989	1.958
1990	1.781
1991	2.15
1992	1.826
1993	3.262
1994	3.541
1995	3.576
1996	2.522
1997	3.371
1998	2.982
1999	3.688
2000	2.109
2001	2.689
2002	5.5
2003	3.821
2004	2.67
2005	2.704
2006	4.357
2007	4.192