Year Percent
1950 2.007
1951 2.206
1952 2.538
1953 2.752
1954 2.883
1955 2.965
1956 3.025
1957 3.088
1958 3.167
1959 3.264
1960 3.361
1961 3.423
1962 3.414
1963 3.307
1964 3.116
1965 2.886
1966 2.663
1967 2.466
1968 2.3
1969 2.168
1970 2.053
1971 1.943
1972 1.844
1973 1.768
1974 1.713
1975 1.671
1976 1.638
1977 1.614
1978 1.599
1979 1.592
1980 1.591
1981 1.591
1982 1.596
1983 1.612
1984 1.634
1985 1.658
1986 1.675
1987 1.678
1988 1.665
1989 1.633
1990 1.595
1991 1.558
1992 1.498
1993 1.397
1994 1.261
1995 1.106
1996 0.957
1997 0.848
1998 0.804
1999 0.824
2000 0.881
2001 0.941
2002 0.991
2003 1.028
2004 1.049
2005 1.062
2006 1.076
2007 1.099
2008 1.134
2009 1.179
2010 1.228
2011 1.271
2012 1.289
2013 1.273
2014 1.222
2015 1.152
2016 1.081
2017 1.01
2018 0.942
2019 0.878
2020 0.815
2021 0.751
2022 0.689
2023 0.634
2024 0.586
2025 0.542
2026 0.5
2027 0.462
2028 0.431
2029 0.405
2030 0.384
2031 0.365
2032 0.346
2033 0.326
2034 0.306
2035 0.286
2036 0.267
2037 0.247
2038 0.225
2039 0.2
2040 0.175
2041 0.149
2042 0.123
2043 0.097
2044 0.071
2045 0.044
2046 0.018
2047 -0.007
2048 -0.031
2049 -0.055
2050 -0.077
2051 -0.099
2052 -0.12
2053 -0.138
2054 -0.155
2055 -0.171
2056 -0.185
2057 -0.199
2058 -0.212
2059 -0.223
2060 -0.234
2061 -0.245
2062 -0.254
2063 -0.264
2064 -0.274
2065 -0.283
2066 -0.292
2067 -0.3
2068 -0.308
2069 -0.315
2070 -0.321
2071 -0.327
2072 -0.333
2073 -0.337
2074 -0.341
2075 -0.345
2076 -0.348
2077 -0.349
2078 -0.35
2079 -0.349
2080 -0.348
2081 -0.345
2082 -0.343
2083 -0.339
2084 -0.335
2085 -0.331
2086 -0.326
2087 -0.322
2088 -0.319
2089 -0.316
2090 -0.314
2091 -0.313
2092 -0.313
2093 -0.313
2094 -0.314
2095 -0.315
2096 -0.318
2097 -0.323
2098 -0.329
2099 -0.338