Year	Percent
1961	3.079
1962	2.4828
1963	-3.30258
1964	7.67994
1965	-1.49637
1966	-0.70362
1967	-5.08137
1968	6.00666
1969	-1.71266
1970	2.97257
1971	-7.43888
1972	-15.46617
1973	1.68051
1974	7.72074
1975	-6.00024
1976	3.21055
1977	0.03276
1978	4.14388
1979	1.88795
1980	-1.94551
1981	4.35152
1982	-0.58039
1983	1.14002
1984	2.03791
1985	0.60599
1986	1.40692
1987	1.02743
1988	-0.25281
1989	0.23199
1990	3.04666
1991	1.06884
1992	3.0778
1993	2.43378
1994	1.66614
1995	2.88561
1996	2.31405
1997	2.30907
1998	3.01995
1999	2.57583
2000	3.2515
2001	3.09815
2002	1.93776
2003	2.91755
2004	3.53517
2005	4.9586
2006	5.25056
2007	5.76992
2008	4.82644
2009	3.89389
2010	4.39611
2011	5.24501
2012	5.27983
2013	4.7728
2014	4.84084
2015	5.36575
2016	5.96269
2017	6.16479