Year	Percent
1960	1.12121
1961	1.44419
1962	1.76546
1963	1.99248
1964	2.08804
1965	2.08976
1966	2.08083
1967	2.07472
1968	2.02327
1969	1.92247
1970	1.78641
1971	1.61144
1972	1.43854
1973	1.27837
1974	1.15224
1975	1.02607
1976	0.93959
1977	0.8129
1978	0.61423
1979	0.27783
1980	-0.11703
1981	-0.51328
1982	-0.84941
1983	-1.12294
1984	-1.28405
1985	-1.3423
1986	-1.40415
1987	-1.41089
1988	-1.16678
1989	-0.6448
1990	0.10351
1991	0.91193
1992	1.65032
1993	2.18417
1994	2.51466
1995	2.61474
1996	2.69234
1997	2.75305
1998	2.68053
1999	2.44937
2000	2.1196
2001	1.74695
2002	1.41139
2003	1.18347
2004	1.09827
2005	1.1222
2006	1.16735
2007	1.1889
2008	1.19332
2009	1.18566
2010	1.14747
2011	1.11147
2012	1.09925
2013	1.07606
2014	1.06865
2015	1.05435
2016	1.03542
2017	1.03363