Year	Percent
1974	4.4
1975	5.3
1977	5.8
1987	7.24
1988	6.99
1989	7.71
1990	5.88
1991	8.19
1992	8.56
1993	7.95
1994	6.68
1995	6.7
1996	10.38
1997	9.17
1998	11.49
1999	13.96
2000	4.8
2001	4.25
2003	5.66
2004	5
2005	3.78
2006	3.55
2007	3.14
2008	3.92
2009	4.61
2010	4.09
2011	3.46
2012	3.23
2013	3.08
2014	3.48
2015	3.62
2016	4.6
2017	3.84
2018	3.53
2019	3.81
2020	6.11