Year	Percent
1972	0.99185
1973	0.99441
1974	0.9904
1989	1.00672
1990	1.00764
1991	1.00696
1992	1.00367
1993	0.99322
1994	0.99352
1995	0.99818
1996	0.99749
1997	0.99008
1998	0.98995
1999	0.98833
2000	0.98562
2001	0.98365
2002	0.98072
2003	0.97568
2004	1.00448
2005	0.99412
2006	0.99022
2007	0.99153
2008	0.99365
2009	0.99443
2010	0.99371
2011	0.99471
2012	0.99648
2013	0.98246
2014	0.98199
2015	0.98676
2016	0.99091