Year	Percent
1960	1.84375
1961	1.57844
1962	1.51934
1963	1.47302
1964	1.41031
1965	1.31677
1966	1.14348
1967	0.98088
1968	0.90705
1969	0.93567
1970	0.96584
1971	1.04071
1972	1.01097
1973	0.88071
1974	0.86835
1975	0.73801
1976	0.72109
1977	0.68163
1978	0.58382
1979	0.73631
1980	0.8429
1981	0.82032
1982	0.84667
1983	0.87884
1984	0.85388
1985	0.87668
1986	0.88819
1987	0.82558
1988	0.99013
1989	0.26266
1990	-0.02707
1991	0.70348
1992	0.77451
1993	0.76856
1994	-1.01303
1995	-2.65971
1996	-2.52203
1997	-1.84751
1998	-0.98239
1999	-0.77854
2000	-0.77107
2001	-0.72462
2002	-0.67251
2003	-1.3015
2004	-1.30269
2005	-1.30411
2006	-1.29716
2007	-1.31421
2008	-1.28207
2009	-1.29872
2010	-1.31581
2011	-1.30754
2012	-1.29872
2013	-1.28932
2014	-1.30616
2015	-0.26598
2016	0.05917
2017	-0.05917