Year	Percent
1960	2.4056
1961	2.69044
1962	3.3335
1963	2.75759
1964	2.84733
1965	2.37974
1966	2.46064
1967	2.32641
1968	1.40799
1969	1.41415
1970	1.86561
1971	1.96732
1972	2.17006
1973	2.35013
1974	2.47291
1975	2.32549
1976	1.19119
1977	0.43173
1978	0.15348
1979	-0.27276
1980	0.24527
1981	0.48419
1982	1.04259
1983	1.40735
1984	0.91423
1985	0.66564
1986	0.10315
1987	1.1539
1988	0.56327
1989	0.76207
1990	1.2021
1991	5.09011
1992	1.22171
1993	1.31748
1994	1.50505
1995	1.63867
1996	1.75433
1997	1.40683
1998	0.98049
1999	0.61861
2000	0.68061
2001	0.6811
2002	1.80798
2003	2.04317
2004	1.55579
2005	1.1983
2006	1.28727
2007	0.86295
2008	0.77917
2009	0.93018
2010	1.0421
2011	0.69282
2012	0.61904
2013	0.83796
2014	1.5799
2015	1.95856
2016	2.16768
2017	2.19933