Year	Percent
1971	7.62134
1972	4.53186
1973	6.29951
1974	7.27529
1975	5.66662
1976	3.30619
1977	3.10072
1978	3.54584
1979	4.27814
1980	5.45119
1981	4.17524
1982	4.58106
1983	2.80794
1984	1.98915
1985	2.12473
1986	2.99954
1987	1.27966
1988	1.69046
1989	2.87907
1990	3.39664
1991	3.08508
1992	5.2868
1993	4.13553
1994	2.16418
1995	1.97553
1996	0.62208
1997	0.26242
1998	0.60812
1999	0.31798
2000	-0.44979
2001	1.277
2002	1.35055
2003	1.20687
2004	1.09373
2005	0.62069
2006	0.30405
2007	1.69739
2008	0.83879
2009	1.75699
2010	0.7577
2011	1.07048
2012	1.54029
2013	1.96539
2014	1.79439
2015	2.01305
2016	1.32921
2017	1.53747