Year	Percent
1970	4.82025
1971	3.90062
1972	2.1889
1973	1.4714
1974	1.8321
1975	1.77535
1976	1.51845
1977	1.55872
1978	1.3321
1979	0.31098
1980	1.39798
1981	1.09674
1982	-0.01758
1983	0.55904
1984	0.66309
1985	0.7176
1986	0.8167
1987	1.52738
1988	1.97421
1989	1.64508
1990	1.87738
1991	1.48957
1992	1.58239
1993	1.44713
1994	1.41023
1995	2.49598
1996	0.52901
1997	2.10112
1998	3.22897
1999	6.04311
2000	4.0691
2001	4.24972
2002	3.38415
2003	2.84865
2004	4.118
2005	3.09643
2006	4.01061
2007	5.10056
2008	5.65015
2009	3.50438
2010	3.37181
2011	3.80117
2012	5.63143
2013	2.55323
2014	3.61053
2015	3.23726
2016	3.47802
2017	4.73742