Year Percent
1950 2.741
1951 2.855
1952 3.051
1953 3.193
1954 3.295
1955 3.367
1956 3.423
1957 3.47
1958 3.514
1959 3.555
1960 3.588
1961 3.601
1962 3.581
1963 3.519
1964 3.421
1965 3.308
1966 3.201
1967 3.09
1968 2.967
1969 2.837
1970 2.707
1971 2.587
1972 2.501
1973 2.468
1974 2.484
1975 2.524
1976 2.563
1977 2.596
1978 2.625
1979 2.646
1980 2.666
1981 2.686
1982 2.693
1983 2.676
1984 2.638
1985 2.586
1986 2.535
1987 2.499
1988 2.491
1989 2.508
1990 2.53
1991 2.542
1992 2.538
1993 2.518
1994 2.48
1995 2.436
1996 2.389
1997 2.318
1998 2.204
1999 2.055
2000 1.888
2001 1.725
2002 1.59
2003 1.501
2004 1.455
2005 1.433
2006 1.412
2007 1.382
2008 1.341
2009 1.29
2010 1.235
2011 1.183
2012 1.138
2013 1.099
2014 1.066
2015 1.037
2016 1.008
2017 0.978
2018 0.945
2019 0.91
2020 0.874
2021 0.839
2022 0.805
2023 0.772
2024 0.741
2025 0.711
2026 0.682
2027 0.652
2028 0.623
2029 0.594
2030 0.566
2031 0.538
2032 0.51
2033 0.484
2034 0.459
2035 0.434
2036 0.41
2037 0.386
2038 0.362
2039 0.339
2040 0.316
2041 0.293
2042 0.271
2043 0.248
2044 0.224
2045 0.201
2046 0.178
2047 0.155
2048 0.133
2049 0.11
2050 0.088
2051 0.067
2052 0.045
2053 0.024
2054 0.003
2055 -0.017
2056 -0.037
2057 -0.057
2058 -0.075
2059 -0.092
2060 -0.108
2061 -0.124
2062 -0.14
2063 -0.155
2064 -0.17
2065 -0.185
2066 -0.199
2067 -0.214
2068 -0.229
2069 -0.244
2070 -0.259
2071 -0.273
2072 -0.288
2073 -0.303
2074 -0.318
2075 -0.333
2076 -0.347
2077 -0.361
2078 -0.373
2079 -0.385
2080 -0.395
2081 -0.405
2082 -0.413
2083 -0.42
2084 -0.426
2085 -0.431
2086 -0.434
2087 -0.437
2088 -0.439
2089 -0.439
2090 -0.439
2091 -0.438
2092 -0.436
2093 -0.434
2094 -0.431
2095 -0.429
2096 -0.426
2097 -0.422
2098 -0.419
2099 -0.415