Year	Percent
1981	1.04027
1982	1.03362
1983	1.0219
1984	1.02389
1985	1.02175
1986	1.02389
1987	1.01235
1990	0.99807
1991	0.99861
1993	0.98906
1994	0.99156
1995	1.00147
1996	0.9937
1998	1.0312
2000	0.99558
2001	1.00364
2002	0.999
2003	1.00162
2004	1.00801
2005	1.00478
2006	1.0026
2007	1.00307
2008	0.99971
2009	1.01006
2010	1.00138
2011	1.00569
2012	0.99556
2013	0.99705
2014	1.00418
2015	1.00635