Year	Percent
1961	5.34178
1962	3.97394
1963	5.14661
1964	7.17577
1965	5.02329
1966	4.72384
1967	7.36206
1968	12.06377
1969	4.15033
1970	7.14819
1971	7.3641
1972	8.24407
1973	13.77204
1974	22.0714
1975	13.56799
1976	13.12468
1977	9.41866
1978	7.45419
1979	8.30498
1980	9.63558
1981	11.65333
1982	9.06772
1983	8.20105
1984	8.45794
1985	5.22646
1986	4.78684
1987	4.27566
1988	7.67847
1989	6.53366
1990	5.20208
1991	1.55875
1992	0.92917
1993	1.8037
1994	1.84252
1995	4.19644
1996	-0.09984
1997	2.11858
1998	3.11143
1999	0.9473
2000	1.63049
2001	3.33343
2002	0.97028
2003	0.21365
2004	0.60774
2005	0.92362
2006	0.91245
2007	2.76504
2008	3.07688
2009	1.87741
2010	0.35077
2011	2.58402
2012	2.95356
2013	2.55172
2014	1.69289
2015	1.87238
2016	0.7909
2017	0.93246