Year Percent
1950 3.522
1951 3.545
1952 3.569
1953 3.557
1954 3.522
1955 3.477
1956 3.431
1957 3.393
1958 3.366
1959 3.35
1960 3.341
1961 3.328
1962 3.298
1963 3.243
1964 3.167
1965 3.081
1966 3.002
1967 2.939
1968 2.901
1969 2.885
1970 2.881
1971 2.877
1972 2.867
1973 2.85
1974 2.826
1975 2.798
1976 2.773
1977 2.755
1978 2.745
1979 2.744
1980 2.744
1981 2.742
1982 2.735
1983 2.726
1984 2.713
1985 2.697
1986 2.679
1987 2.653
1988 2.616
1989 2.569
1990 2.516
1991 2.463
1992 2.414
1993 2.371
1994 2.334
1995 2.298
1996 2.26
1997 2.223
1998 2.19
1999 2.16
2000 2.135
2001 2.109
2002 2.07
2003 2.004
2004 1.915
2005 1.815
2006 1.72
2007 1.648
2008 1.613
2009 1.613
2010 1.631
2011 1.648
2012 1.653
2013 1.643
2014 1.616
2015 1.582
2016 1.55
2017 1.521
2018 1.497
2019 1.476
2020 1.457
2021 1.437
2022 1.415
2023 1.391
2024 1.365
2025 1.337
2026 1.31
2027 1.283
2028 1.255
2029 1.228
2030 1.2
2031 1.172
2032 1.145
2033 1.117
2034 1.09
2035 1.063
2036 1.036
2037 1.009
2038 0.983
2039 0.958
2040 0.933
2041 0.908
2042 0.884
2043 0.86
2044 0.837
2045 0.813
2046 0.79
2047 0.768
2048 0.747
2049 0.727
2050 0.707
2051 0.687
2052 0.667
2053 0.647
2054 0.626
2055 0.604
2056 0.583
2057 0.562
2058 0.542
2059 0.523
2060 0.503
2061 0.484
2062 0.465
2063 0.446
2064 0.427
2065 0.409
2066 0.39
2067 0.372
2068 0.354
2069 0.337
2070 0.32
2071 0.303
2072 0.286
2073 0.269
2074 0.253
2075 0.237
2076 0.221
2077 0.206
2078 0.19
2079 0.176
2080 0.162
2081 0.148
2082 0.134
2083 0.122
2084 0.109
2085 0.098
2086 0.086
2087 0.075
2088 0.064
2089 0.054
2090 0.043
2091 0.032
2092 0.022
2093 0.012
2094 0.002
2095 -0.008
2096 -0.017
2097 -0.027
2098 -0.037
2099 -0.047