Year Percent
1950 2.444
1951 2.529
1952 2.65
1953 2.687
1954 2.678
1955 2.656
1956 2.651
1957 2.685
1958 2.773
1959 2.915
1960 3.093
1961 3.272
1962 3.41
1963 3.481
1964 3.495
1965 3.487
1966 3.5
1967 3.58
1968 3.752
1969 4.002
1970 4.288
1971 4.562
1972 4.788
1973 4.95
1974 5.057
1975 5.108
1976 5.131
1977 5.225
1978 5.45
1979 5.765
1980 6.08
1981 6.298
1982 6.322
1983 6.113
1984 5.718
1985 5.257
1986 4.826
1987 4.434
1988 4.065
1989 3.723
1990 3.41
1991 3.122
1992 2.857
1993 2.613
1994 2.394
1995 2.192
1996 2.013
1997 1.925
1998 1.982
1999 2.17
2000 2.427
2001 2.677
2002 2.857
2003 2.931
2004 2.905
2005 2.823
2006 2.741
2007 2.698
2008 2.715
2009 2.783
2010 2.872
2011 2.939
2012 2.934
2013 2.824
2014 2.623
2015 2.378
2016 2.142
2017 1.943
2018 1.793
2019 1.693
2020 1.617
2021 1.541
2022 1.465
2023 1.395
2024 1.33
2025 1.271
2026 1.216
2027 1.165
2028 1.116
2029 1.067
2030 1.021
2031 0.977
2032 0.934
2033 0.888
2034 0.841
2035 0.792
2036 0.746
2037 0.705
2038 0.672
2039 0.647
2040 0.627
2041 0.607
2042 0.587
2043 0.566
2044 0.544
2045 0.521
2046 0.499
2047 0.476
2048 0.452
2049 0.425
2050 0.396
2051 0.368
2052 0.339
2053 0.309
2054 0.278
2055 0.247
2056 0.216
2057 0.186
2058 0.156
2059 0.127
2060 0.099
2061 0.072
2062 0.047
2063 0.025
2064 0.005
2065 -0.013
2066 -0.029
2067 -0.044
2068 -0.056
2069 -0.067
2070 -0.075
2071 -0.083
2072 -0.089
2073 -0.094
2074 -0.099
2075 -0.102
2076 -0.106
2077 -0.109
2078 -0.112
2079 -0.115
2080 -0.118
2081 -0.121
2082 -0.125
2083 -0.13
2084 -0.136
2085 -0.142
2086 -0.149
2087 -0.156
2088 -0.164
2089 -0.172
2090 -0.18
2091 -0.189
2092 -0.198
2093 -0.207
2094 -0.217
2095 -0.227
2096 -0.237
2097 -0.248
2098 -0.258
2099 -0.269