Year	Percent
1977	5.44
1979	6.45
1981	7.5
1982	8.86
1983	12.49
1984	13.85
1985	13.62
1986	11.33
1987	9.83
1988	7.76
1989	10.05
1994	8.05
1995	8.95
1996	10.33
2002	14.43
2003	14.41
2005	10.0465
2006	8.1146
2007	7.0477
2008	6.2622
2009	6.1834
2010	7.2152
2011	6.7044
2012	6.2679