Year	Percent
1970	1.46831
1972	1.46234
1973	1.43679
1975	1.42215
1976	1.41802
1977	1.43709
1978	1.45188
1979	1.44713
1980	1.42483
1981	1.38255
1982	1.33415
1983	1.31471
1984	1.28553
1985	1.27484
1986	1.28291
1987	1.29922
1988	1.30012
1989	1.28575
1990	1.27753
1991	1.28277
1992	1.26462
1993	1.2449
1994	1.2252
1996	1.18879
1997	1.1654
1998	1.16289
1999	1.13795
2000	1.08932
2001	1.06545
2002	1.0611
2003	1.05827
2004	1.04793
2005	1.04787
2006	1.04735
2007	1.05388
2008	1.06001
2009	1.07676
2010	1.06662
2011	1.06007
2012	1.06276
2013	1.06001
2014	1.0598
2015	1.05651
2016	1.05491