Year	Percent
1961	4.30663
1962	6.6359
1963	5.77348
1964	4.61103
1965	7.43647
1966	6.83266
1967	6.25
1968	6.99916
1969	6.97385
1970	10.73639
1971	7.44541
1972	9.60163
1973	10.62021
1974	13.26615
1975	13.35594
1976	9.38003
1977	8.87586
1978	8.95472
1979	7.0688
1980	8.81059
1981	10.69376
1982	10.14456
1983	7.38594
1984	5.95924
1985	4.29103
1986	2.31552
1987	4.7547
1988	3.94468
1989	4.96527
1990	2.60242
1991	2.65948
1992	1.65585
1993	0.57995
1994	1.56548
1995	1.28244
1996	2.0142
1997	2.01387
1998	1.23221
1999	1.68475
2000	3.01795
2001	2.51836
2002	2.34766
2003	1.4818
2004	2.09579
2005	2.90638
2006	2.07621
2007	2.43226
2008	4.13472
2009	0.52902
2010	3.22406
2011	0.63865
2012	2.37518
2013	0.88817
2014	1.03213
2015	0.70112
2016	-0.04644
2017	1.55534