Year	Percent
1961	6.29396
1962	4.25382
1963	7.7739
1964	3.85594
1965	3.02549
1966	10.02736
1967	5.51605
1968	-1.04473
1969	2.99689
1970	3.71046
1971	8.31302
1972	7.42777
1973	7.83858
1974	8.11374
1975	8.3048
1976	8.67575
1977	14.52453
1978	-0.82834
1979	17.1016
1980	20.14401
1981	27.78913
1982	6.04474
1983	6.33837
1984	12.11139
1985	2.49854
1986	-29.17266
1987	7.62652
1988	-6.22635
1989	12.74406
1990	-1.02907
1991	-1.48064
1992	-1.56927
1993	-1.13083
1994	36.75283
1995	3.39593
1996	17.99192
1997	4.96452
1998	-18.22209
1999	29.35534
2000	47.04008
2001	-13.92521
2002	-1.73893
2003	-4.25154
2004	16.80724
2005	21.32945
2006	18.51937
2007	1.12245
2008	25.02768
2009	-20.62725
2010	20.72208
2011	10.67029
2012	-1.16994
2013	-3.65824
2014	-5.66896
2015	-29.69107
2016	-5.52718
2017	14.55712