Year	Percent
1960	10.96403
1961	6.9274
1962	6.74059
1963	5.17616
1964	4.42007
1965	6.00207
1966	3.85411
1967	4.87587
1968	4.59812
1969	4.19045
1970	4.07885
1971	3.51185
1972	3.02647
1973	2.07759
1974	1.94148
1975	2.12273
1976	4.11861
1977	2.46407
1978	3.78307
1979	5.21559
1980	4.41197
1981	3.9128
1982	3.95338
1983	3.48615
1984	3.6627
1985	4.06768
1986	4.05269
1987	3.25983
1988	2.62828
1989	2.69834
1990	2.24973
1991	1.69602
1992	1.65834
1993	1.13847
1994	0.96289
1995	1.15271
1996	1.06801
1997	1.21395
1998	3.06727
1999	3.97574
2000	2.48787
2001	1.02271
2002	0.97493
2003	-2.58655
2004	0.1168
2005	-0.28577
2006	-0.35754
2007	-0.45828
2008	-0.74837
2009	-0.05338
2010	-0.02354
2011	-0.135
2012	-0.11791
2013	0.02495
2014	0.36386
2015	0.0654
2016	0.26109
2017	0.23907
2018	-0.32808
2019	-0.27145
2020	0.16659
2021	0.09082