Year	Percent
1961	7.78572
1962	4.19958
1963	5.51047
1964	5.32871
1965	5.13686
1966	4.97087
1967	5.49539
1968	4.91886
1969	4.4334
1970	22.97269
1971	5.09135
1972	5.60442
1973	12.7054
1974	20.81005
1975	7.17744
1976	8.00789
1977	6.74911
1978	4.60376
1979	2.75163
1980	5.43798
1981	2.92683
1982	1.74497
1983	0.94566
1984	1.47338
1985	1.26015
1986	1.6122
1987	-0.15789
1988	0.62529
1989	2.10889
1990	2.60531
1991	2.92785
1992	1.66664
1993	0.56837
1994	0.26552
1995	-0.53346
1996	-0.49649
1997	0.50383
1998	-0.04512
1999	-1.30949
2000	-1.38369
2001	-1.10452
2002	-1.45829
2003	-1.61698
2004	-1.10074
2005	-1.03743
2006	-0.88338
2007	-0.72948
2008	-0.9809
2009	-0.61127
2010	-1.89516
2011	-1.67433
2012	-0.76155
2013	-0.33318
2014	1.74531
2015	2.14134
2016	0.27356
2017	-0.21515