Year	Percent
1950	0.475
1951	0.465
1952	0.446
1953	0.433
1954	0.427
1955	0.432
1956	0.45
1957	0.483
1958	0.531
1959	0.594
1960	0.662
1961	0.727
1962	0.773
1963	0.79
1964	0.777
1965	0.748
1966	0.714
1967	0.663
1968	0.58
1969	0.468
1970	0.339
1971	0.209
1972	0.095
1973	0.01
1974	-0.044
1975	-0.078
1976	-0.105
1977	-0.13
1978	-0.157
1979	-0.184
1980	-0.21
1981	-0.228
1982	-0.216
1983	-0.155
1984	-0.047
1985	0.086
1986	0.216
1987	0.331
1988	0.422
1989	0.485
1990	0.536
1991	0.583
1992	0.597
1993	0.55
1994	0.445
1995	0.305
1996	0.159
1997	0.045
1998	-0.011
1999	-0.007
2000	0.033
2001	0.076
2002	0.092
2003	0.064
2004	-0.009
2005	-0.107
2006	-0.2
2007	-0.252
2008	-0.233
2009	-0.146
2010	-0.02
2011	0.106
2012	0.204
2013	0.26
2014	0.272
2015	0.26
2016	0.248
2017	0.231
2018	0.197
2019	0.15
2020	0.092
2021	0.031
2022	-0.021
2023	-0.052
2024	-0.062
2025	-0.06
2026	-0.058
2027	-0.059
2028	-0.065
2029	-0.075
2030	-0.087
2031	-0.098
2032	-0.107
2033	-0.116
2034	-0.125
2035	-0.133
2036	-0.141
2037	-0.15
2038	-0.159
2039	-0.169
2040	-0.179
2041	-0.19
2042	-0.2
2043	-0.211
2044	-0.222
2045	-0.233
2046	-0.243
2047	-0.253
2048	-0.264
2049	-0.274
2050	-0.283
2051	-0.292
2052	-0.298
2053	-0.303
2054	-0.304
2055	-0.304
2056	-0.303
2057	-0.3
2058	-0.295
2059	-0.287
2060	-0.278
2061	-0.268
2062	-0.258
2063	-0.247
2064	-0.237
2065	-0.228
2066	-0.218
2067	-0.21
2068	-0.204
2069	-0.201
2070	-0.2
2071	-0.2
2072	-0.201
2073	-0.203
2074	-0.207
2075	-0.212
2076	-0.217
2077	-0.222
2078	-0.225
2079	-0.227
2080	-0.229
2081	-0.23
2082	-0.229
2083	-0.226
2084	-0.22
2085	-0.213
2086	-0.205
2087	-0.197
2088	-0.189
2089	-0.181
2090	-0.173
2091	-0.165
2092	-0.157
2093	-0.15
2094	-0.144
2095	-0.138
2096	-0.134
2097	-0.131
2098	-0.13
2099	-0.131