Year	Percent
1971	0.99744
1972	1.00112
1973	1.01873
1974	1.00588
1975	0.96081
1976	1.0111
1977	0.97329
1978	0.99107
1979	0.98657
1986	1.06046
1987	1.08184
1988	1.09347
1989	1.08477
1990	1.15831
1991	1.07458
1992	1.06378
1993	1.0285
2001	1.06652
2002	1.13368
2005	1.11221
2006	1.12657
2007	1.12331
2008	1.11062
2009	1.08726
2010	1.10116
2011	1.12869
2012	1.12879
2013	1.14159
2014	1.15134
2015	1.1306