Year	Percent
1971	0.94228
1972	0.94287
1973	0.94534
1974	0.95506
1975	0.96266
1976	0.96054
1977	0.96347
1978	0.96416
1979	0.98203
1980	0.97091
1981	0.97936
1983	0.99744
1984	1.00325
1985	0.99656
1986	1.0002
1987	1.00098
1988	1.00315
1993	0.99596
1996	1.00764
1998	1.00989
1999	1.0072
2000	1.00151
2001	1.00613
2002	1.00089
2003	1.00394
2004	0.99834
2005	1.00051
2006	1.00145
2007	1.00211
2010	1.02254
2011	1.01738
2012	1.01928
2013	1.02427
2014	1.02063
2015	1.01985
2016	1.02017
2017	1.01899