Year	Percent
1960	1.2135
1961	0.46272
1962	-0.18452
1963	-0.39655
1964	0.05452
1965	0.90538
1966	1.9365
1967	2.70295
1968	3.15139
1969	3.08556
1970	2.74704
1971	2.30973
1972	2.01798
1973	1.89711
1974	2.06405
1975	2.37277
1976	2.7203
1977	2.95868
1978	2.99138
1979	2.80201
1980	2.45217
1981	2.08555
1982	1.79504
1983	1.61994
1984	1.5794
1985	1.67263
1986	1.7599
1987	1.82354
1988	1.89507
1989	1.95124
1990	2.00965
1991	2.08621
1992	2.14546
1993	2.15725
1994	2.09153
1995	1.98148
1996	1.85452
1997	1.75899
1998	1.74733
1999	1.83292
2000	1.98191
2001	2.15262
2002	2.28064
2003	2.37547
2004	2.39539
2005	2.38048
2006	2.34836
2007	2.34047
2008	2.31031
2009	2.30967
2010	2.29358
2011	2.27627
2012	2.26115
2013	2.24698
2014	2.23159
2015	2.21663
2016	2.20358
2017	2.18544