Year	Percent
1960	5.69014
1961	5.42152
1962	5.11532
1963	4.76722
1964	4.38918
1965	4.19855
1966	3.7917
1967	3.41728
1968	3.14375
1969	2.99488
1970	2.8163
1971	2.65409
1972	2.61554
1973	2.54992
1974	2.43504
1975	1.81868
1976	1.68116
1977	1.5744
1978	1.51725
1979	1.67358
1980	1.90353
1981	1.93851
1982	1.95535
1983	1.97594
1984	2.00226
1985	1.43091
1986	1.47475
1987	1.47486
1988	1.33284
1989	1.68511
1990	0.44274
1991	0.46316
1992	-0.23325
1993	-0.82567
1994	-1.6153
1995	-1.7147
1996	-1.47522
1997	-1.54242
1998	-1.6868
1999	-0.88287
2000	-0.17033
2001	-0.04003
2002	0.13401
2003	0.46611
2004	0.82446
2005	1.01827
2006	1.18687
2007	1.2729
2008	1.34724
2009	2.76571
2010	1.54005
2011	1.55988
2012	1.5369
2013	1.56749
2014	1.59881
2015	1.5892
2016	1.54961
2017	1.48531