Year	Percent
1960	4.33909
1961	4.78847
1962	4.90958
1963	4.90775
1964	4.91659
1965	4.92476
1966	4.93585
1967	4.942
1968	4.94857
1969	4.94836
1970	4.95422
1971	4.34275
1972	4.17452
1973	4.17509
1974	4.16238
1975	4.13919
1976	4.10602
1977	4.07554
1978	4.08317
1979	4.12305
1980	4.187
1981	4.2469
1982	4.06905
1983	4.00974
1984	3.93893
1985	3.82943
1986	3.7186
1987	3.62049
1988	3.53406
1989	3.46487
1990	3.4085
1991	3.34622
1992	3.28285
1993	3.23998
1994	3.22349
1995	3.4787
1996	3.55034
1997	3.54742
1998	3.48332
1999	3.33418
2000	3.14773
2001	2.85042
2002	2.59738
2003	2.59186
2004	2.91372
2005	3.3845
2006	4.00927
2007	4.39664
2008	4.13269
2009	3.08507
2010	1.58201
2011	-2.59098
2012	-4.04341
2013	-4.97493
2014	-5.0856
2015	-1.1791
2016	-0.36838
2017	0.37565