Year	Percent
1960	4.44091
1961	4.29039
1962	4.31818
1963	4.30511
1964	4.26135
1965	4.00172
1966	3.95085
1967	3.91382
1968	3.85058
1969	3.74076
1970	3.76688
1971	3.82968
1972	3.73106
1973	3.58848
1974	3.42854
1975	2.95673
1976	2.8408
1977	2.8588
1978	2.90506
1979	2.72431
1980	2.57267
1981	2.59635
1982	2.53558
1983	2.49386
1984	2.44388
1985	2.33851
1986	2.32191
1987	2.27355
1988	1.84304
1989	1.3885
1990	0.78864
1991	0.64293
1992	0.80444
1993	0.80581
1994	0.45588
1995	0.2452
1996	0.22672
1997	0.12918
1998	0.07178
1999	0.18281
2000	0.23305
2001	0.17776
2002	0.04379
2003	-0.03105
2004	-0.02341
2005	-0.03548
2006	0.0242
2007	0.16681
2008	0.27092
2009	0.38017
2010	0.50148
2011	0.50503
2012	0.58305
2013	0.67685
2014	0.73612
2015	0.79359
2016	0.74549
2017	0.67393