Year	Percent
1974	0.54042
1975	4.82041
1976	1.33808
1977	0.83663
1978	1.37606
1979	0.67464
1980	0.2751
1981	0.74986
1982	0.39729
1983	0.29371
1984	0.00369
1985	0.34213
1986	0.49797
1987	0.41429
1988	0.63364
1989	0.41424
1990	0.55355
1991	0.36869
1992	0.74068
1993	0.45939
1994	0.60196
1995	0.51946
1996	0.55144
1997	0.58055
1998	0.54793
1999	0.57601
2000	0.6215
2001	0.59519
2002	0.54897
2003	1.77871
2004	-0.3443
2005	6.1135
2006	8.05926
2007	9.98518
2008	10.02839
2009	10.33267
2010	14.99059
2011	8.31675
2012	9.38875
2013	-0.17525
2014	12.13755
2015	1.51586
2016	5.07042
2017	5.96553