Year	Percent
1986	1.01
1987	0.67
1988	0.64
1989	0.75
1990	1.22
1991	1.3
1992	1.21
1993	1.11
1994	1.08
1995	1.07
1996	1.21
1997	0.92
1998	0.9
1999	0.93
2000	0.85
2001	0.87
2002	0.79
2003	0.69
2004	0.57
2005	0.62
2006	0.92
2007	1.11
2008	0.96
2009	1.07
2010	1.07
2011	1.03
2012	1.04
2013	1.16
2014	1.04
2015	0.91
2016	0.9
2017	0.78