Year	Percent
1950	0.904
1951	0.865
1952	0.785
1953	0.705
1954	0.631
1955	0.572
1956	0.535
1957	0.525
1958	0.546
1959	0.597
1960	0.669
1961	0.744
1962	0.8
1963	0.82
1964	0.804
1965	0.767
1966	0.729
1967	0.7
1968	0.685
1969	0.684
1970	0.688
1971	0.688
1972	0.674
1973	0.641
1974	0.589
1975	0.526
1976	0.463
1977	0.405
1978	0.358
1979	0.322
1980	0.292
1981	0.263
1982	0.231
1983	0.194
1984	0.153
1985	0.109
1986	0.068
1987	0.036
1988	0.021
1989	0.021
1990	0.034
1991	0.054
1992	0.065
1993	0.055
1994	0.025
1995	-0.019
1996	-0.061
1997	-0.067
1998	-0.004
1999	0.122
2000	0.285
2001	0.441
2002	0.554
2003	0.596
2004	0.566
2005	0.498
2006	0.428
2007	0.356
2008	0.276
2009	0.191
2010	0.099
2011	0.003
2012	-0.077
2013	-0.124
2014	-0.137
2015	-0.131
2016	-0.121
2017	-0.117
2018	-0.121
2019	-0.134
2020	-0.151
2021	-0.165
2022	-0.174
2023	-0.178
2024	-0.179
2025	-0.177
2026	-0.174
2027	-0.173
2028	-0.175
2029	-0.179
2030	-0.185
2031	-0.191
2032	-0.196
2033	-0.202
2034	-0.207
2035	-0.213
2036	-0.219
2037	-0.227
2038	-0.235
2039	-0.244
2040	-0.255
2041	-0.265
2042	-0.277
2043	-0.289
2044	-0.302
2045	-0.316
2046	-0.33
2047	-0.344
2048	-0.359
2049	-0.375
2050	-0.391
2051	-0.406
2052	-0.42
2053	-0.433
2054	-0.444
2055	-0.454
2056	-0.462
2057	-0.469
2058	-0.472
2059	-0.472
2060	-0.47
2061	-0.466
2062	-0.46
2063	-0.45
2064	-0.438
2065	-0.424
2066	-0.408
2067	-0.391
2068	-0.373
2069	-0.354
2070	-0.334
2071	-0.313
2072	-0.293
2073	-0.273
2074	-0.255
2075	-0.237
2076	-0.22
2077	-0.205
2078	-0.192
2079	-0.181
2080	-0.173
2081	-0.165
2082	-0.159
2083	-0.155
2084	-0.151
2085	-0.15
2086	-0.149
2087	-0.148
2088	-0.148
2089	-0.149
2090	-0.149
2091	-0.15
2092	-0.152
2093	-0.153
2094	-0.155
2095	-0.157
2096	-0.159
2097	-0.161
2098	-0.162
2099	-0.162