Year	Percent
1979	0.9683
1980	1.0418
1981	1.7558
1982	0.7643
1983	0.3659
1984	1.1593
1985	1.5676
1986	0.85
1987	0.6754
1988	0.9162
1989	1.1449
1990	1.8885
1991	0.9937
1992	1.4756
1993	1.0615
1994	1.7179
1995	1.2047
1996	1.2666
1997	1.4392
1998	1.2136
1999	0.7626
2000	0.6893
2001	1.3305
2002	0.664
2003	0.8885
2004	0.7681
2005	1.4428
2006	1.2282
2007	1.1002
2008	1.2141
2009	0.987
2010	1.2126
2011	1.1168
2012	1.1494
2013	1.1831
2014	1.6172
2015	1.37
2016	1.194
2017	1.0931