Year Percent
1950 2.208
1951 2.008
1952 1.621
1953 1.264
1954 0.948
1955 0.681
1956 0.469
1957 0.323
1958 0.247
1959 0.241
1960 0.288
1961 0.355
1962 0.41
1963 0.42
1964 0.381
1965 0.318
1966 0.264
1967 0.244
1968 0.272
1969 0.346
1970 0.444
1971 0.54
1972 0.609
1973 0.637
1974 0.625
1975 0.59
1976 0.556
1977 0.52
1978 0.479
1979 0.43
1980 0.377
1981 0.325
1982 0.283
1983 0.266
1984 0.275
1985 0.301
1986 0.329
1987 0.348
1988 0.357
1989 0.356
1990 0.349
1991 0.346
1992 0.346
1993 0.348
1994 0.354
1995 0.364
1996 0.373
1997 0.376
1998 0.369
1999 0.353
2000 0.327
2001 0.301
2002 0.29
2003 0.296
2004 0.321
2005 0.355
2006 0.389
2007 0.413
2008 0.418
2009 0.404
2010 0.381
2011 0.359
2012 0.339
2013 0.319
2014 0.301
2015 0.283
2016 0.264
2017 0.244
2018 0.225
2019 0.206
2020 0.184
2021 0.167
2022 0.149
2023 0.127
2024 0.105
2025 0.086
2026 0.064
2027 0.043
2028 0.023
2029 0.001
2030 -0.018
2031 -0.038
2032 -0.058
2033 -0.075
2034 -0.095
2035 -0.114
2036 -0.131
2037 -0.146
2038 -0.161
2039 -0.176
2040 -0.187
2041 -0.198
2042 -0.21
2043 -0.219
2044 -0.228
2045 -0.235
2046 -0.24
2047 -0.246
2048 -0.251
2049 -0.253
2050 -0.253
2051 -0.255
2052 -0.256
2053 -0.252
2054 -0.249
2055 -0.246
2056 -0.243
2057 -0.242
2058 -0.236
2059 -0.229
2060 -0.224
2061 -0.218
2062 -0.213
2063 -0.207
2064 -0.202
2065 -0.198
2066 -0.192
2067 -0.188
2068 -0.184
2069 -0.18
2070 -0.177
2071 -0.172
2072 -0.169
2073 -0.167
2074 -0.164
2075 -0.162
2076 -0.161
2077 -0.16
2078 -0.158
2079 -0.159
2080 -0.159
2081 -0.16
2082 -0.161
2083 -0.16
2084 -0.161
2085 -0.162
2086 -0.163
2087 -0.162
2088 -0.164
2089 -0.167
2090 -0.168
2091 -0.168
2092 -0.169
2093 -0.173
2094 -0.174
2095 -0.172
2096 -0.174
2097 -0.174
2098 -0.173
2099 -0.176