Year Percent
1950 2.61
1951 2.709
1952 2.855
1953 2.915
1954 2.923
1955 2.906
1956 2.892
1957 2.9
1958 2.943
1959 3.018
1960 3.108
1961 3.18
1962 3.196
1963 3.128
1964 2.987
1965 2.815
1966 2.655
1967 2.529
1968 2.443
1969 2.399
1970 2.375
1971 2.352
1972 2.341
1973 2.359
1974 2.399
1975 2.456
1976 2.518
1977 2.557
1978 2.552
1979 2.508
1980 2.442
1981 2.379
1982 2.366
1983 2.431
1984 2.566
1985 2.733
1986 2.884
1987 2.972
1988 2.969
1989 2.883
1990 2.755
1991 2.63
1992 2.54
1993 2.498
1994 2.503
1995 2.528
1996 2.544
1997 2.528
1998 2.468
1999 2.367
2000 2.25
2001 2.139
2002 2.046
2003 1.976
2004 1.928
2005 1.889
2006 1.849
2007 1.817
2008 1.806
2009 1.813
2010 1.831
2011 1.847
2012 1.837
2013 1.781
2014 1.682
2015 1.562
2016 1.445
2017 1.353
2018 1.296
2019 1.274
2020 1.27
2021 1.264
2022 1.249
2023 1.223
2024 1.185
2025 1.142
2026 1.101
2027 1.061
2028 1.02
2029 0.978
2030 0.935
2031 0.892
2032 0.851
2033 0.812
2034 0.775
2035 0.739
2036 0.704
2037 0.672
2038 0.643
2039 0.617
2040 0.593
2041 0.571
2042 0.551
2043 0.533
2044 0.517
2045 0.503
2046 0.49
2047 0.477
2048 0.463
2049 0.449
2050 0.434
2051 0.42
2052 0.404
2053 0.387
2054 0.368
2055 0.349
2056 0.328
2057 0.307
2058 0.285
2059 0.263
2060 0.239
2061 0.215
2062 0.191
2063 0.166
2064 0.141
2065 0.115
2066 0.09
2067 0.065
2068 0.041
2069 0.018
2070 -0.004
2071 -0.026
2072 -0.046
2073 -0.064
2074 -0.08
2075 -0.095
2076 -0.109
2077 -0.122
2078 -0.132
2079 -0.141
2080 -0.149
2081 -0.155
2082 -0.161
2083 -0.165
2084 -0.168
2085 -0.171
2086 -0.172
2087 -0.174
2088 -0.175
2089 -0.176
2090 -0.177
2091 -0.178
2092 -0.179
2093 -0.181
2094 -0.182
2095 -0.184
2096 -0.187
2097 -0.19
2098 -0.194
2099 -0.199