Year Percent
1950 1.713
1951 1.909
1952 2.25
1953 2.496
1954 2.657
1955 2.744
1956 2.768
1957 2.741
1958 2.672
1959 2.571
1960 2.447
1961 2.31
1962 2.166
1963 2.023
1964 1.887
1965 1.749
1966 1.611
1967 1.496
1968 1.428
1969 1.402
1970 1.403
1971 1.408
1972 1.385
1973 1.315
1974 1.199
1975 1.06
1976 0.926
1977 0.834
1978 0.81
1979 0.851
1980 0.924
1981 0.988
1982 1.025
1983 1.026
1984 0.988
1985 0.932
1986 0.872
1987 0.79
1988 0.664
1989 0.497
1990 0.311
1991 0.128
1992 -0.045
1993 -0.206
1994 -0.351
1995 -0.491
1996 -0.628
1997 -0.717
1998 -0.713
1999 -0.617
2000 -0.461
2001 -0.292
2002 -0.166
2003 -0.123
2004 -0.167
2005 -0.26
2006 -0.351
2007 -0.403
2008 -0.396
2009 -0.329
2010 -0.228
2011 -0.132
2012 -0.066
2013 -0.046
2014 -0.074
2015 -0.127
2016 -0.182
2017 -0.229
2018 -0.266
2019 -0.29
2020 -0.31
2021 -0.334
2022 -0.36
2023 -0.387
2024 -0.414
2025 -0.441
2026 -0.468
2027 -0.496
2028 -0.524
2029 -0.553
2030 -0.583
2031 -0.612
2032 -0.639
2033 -0.664
2034 -0.686
2035 -0.706
2036 -0.726
2037 -0.745
2038 -0.761
2039 -0.775
2040 -0.787
2041 -0.799
2042 -0.811
2043 -0.822
2044 -0.834
2045 -0.846
2046 -0.857
2047 -0.869
2048 -0.882
2049 -0.895
2050 -0.908
2051 -0.922
2052 -0.936
2053 -0.952
2054 -0.969
2055 -0.987
2056 -1.005
2057 -1.023
2058 -1.043
2059 -1.064
2060 -1.086
2061 -1.107
2062 -1.128
2063 -1.148
2064 -1.166
2065 -1.184
2066 -1.2
2067 -1.214
2068 -1.227
2069 -1.237
2070 -1.246
2071 -1.252
2072 -1.254
2073 -1.252
2074 -1.245
2075 -1.234
2076 -1.221
2077 -1.205
2078 -1.186
2079 -1.164
2080 -1.14
2081 -1.115
2082 -1.089
2083 -1.062
2084 -1.036
2085 -1.01
2086 -0.983
2087 -0.958
2088 -0.934
2089 -0.912
2090 -0.892
2091 -0.873
2092 -0.856
2093 -0.841
2094 -0.827
2095 -0.814
2096 -0.805
2097 -0.798
2098 -0.796
2099 -0.797