Year Percent
1950 0.618
1951 0.659
1952 0.729
1953 0.776
1954 0.808
1955 0.832
1956 0.856
1957 0.886
1958 0.928
1959 0.981
1960 1.041
1961 1.096
1962 1.134
1963 1.143
1964 1.124
1965 1.089
1966 1.052
1967 1.03
1968 1.034
1969 1.063
1970 1.103
1971 1.135
1972 1.153
1973 1.154
1974 1.138
1975 1.113
1976 1.084
1977 1.04
1978 0.971
1979 0.88
1980 0.776
1981 0.674
1982 0.578
1983 0.491
1984 0.416
1985 0.348
1986 0.284
1987 0.235
1988 0.21
1989 0.21
1990 0.231
1991 0.266
1992 0.298
1993 0.314
1994 0.317
1995 0.307
1996 0.301
1997 0.353
1998 0.506
1999 0.753
2000 1.04
2001 1.305
2002 1.501
2003 1.601
2004 1.603
2005 1.56
2006 1.511
2007 1.402
2008 1.178
2009 0.852
2010 0.464
2011 0.073
2012 -0.226
2013 -0.359
2014 -0.322
2015 -0.188
2016 -0.047
2017 0.054
2018 0.093
2019 0.067
2020 0.009
2021 -0.038
2022 -0.068
2023 -0.084
2024 -0.086
2025 -0.082
2026 -0.079
2027 -0.08
2028 -0.082
2029 -0.088
2030 -0.095
2031 -0.102
2032 -0.108
2033 -0.114
2034 -0.119
2035 -0.123
2036 -0.129
2037 -0.136
2038 -0.144
2039 -0.154
2040 -0.166
2041 -0.178
2042 -0.192
2043 -0.209
2044 -0.228
2045 -0.249
2046 -0.27
2047 -0.293
2048 -0.317
2049 -0.343
2050 -0.371
2051 -0.398
2052 -0.424
2053 -0.45
2054 -0.473
2055 -0.496
2056 -0.517
2057 -0.537
2058 -0.554
2059 -0.569
2060 -0.581
2061 -0.591
2062 -0.599
2063 -0.603
2064 -0.605
2065 -0.603
2066 -0.599
2067 -0.592
2068 -0.582
2069 -0.569
2070 -0.553
2071 -0.535
2072 -0.514
2073 -0.491
2074 -0.465
2075 -0.437
2076 -0.409
2077 -0.381
2078 -0.354
2079 -0.328
2080 -0.304
2081 -0.281
2082 -0.26
2083 -0.243
2084 -0.231
2085 -0.221
2086 -0.214
2087 -0.209
2088 -0.206
2089 -0.207
2090 -0.21
2091 -0.214
2092 -0.22
2093 -0.226
2094 -0.233
2095 -0.241
2096 -0.249
2097 -0.258
2098 -0.267
2099 -0.277