Year	Percent
1960	-0.49349
1961	1.61918
1962	3.54085
1963	4.70129
1964	5.14684
1965	5.07869
1966	4.98224
1967	4.87007
1968	4.37708
1969	3.47604
1970	2.35796
1971	1.20913
1972	0.20575
1973	-0.55376
1974	-0.91556
1975	-0.9367
1976	-0.91099
1977	-0.86814
1978	-0.50696
1979	0.23719
1980	1.22491
1981	2.34326
1982	3.38768
1983	4.01526
1984	4.28829
1985	4.30587
1986	4.28664
1987	4.26299
1988	4.08178
1989	3.73989
1990	3.312
1991	2.85974
1992	2.46212
1993	2.18041
1994	2.05948
1995	2.04258
1996	2.09271
1997	2.03164
1998	2.03926
1999	2.11658
2000	2.21488
2001	2.33297
2002	2.43874
2003	2.47548
2004	2.42734
2005	2.32838
2006	2.20549
2007	2.1067
2008	2.06751
2009	2.10942
2010	2.19461
2011	2.29574
2012	2.35485
2013	2.33853
2014	2.22227
2015	2.04441
2016	1.85067
2017	1.68461