Year Percent
1950 0.144
1951 0.213
1952 0.353
1953 0.495
1954 0.636
1955 0.774
1956 0.906
1957 1.031
1958 1.147
1959 1.253
1960 1.351
1961 1.444
1962 1.537
1963 1.633
1964 1.73
1965 1.826
1966 1.918
1967 1.999
1968 2.065
1969 2.117
1970 2.161
1971 2.204
1972 2.252
1973 2.309
1974 2.375
1975 2.445
1976 2.513
1977 2.573
1978 2.625
1979 2.669
1980 2.711
1981 2.755
1982 2.797
1983 2.835
1984 2.869
1985 2.894
1986 2.914
1987 2.957
1988 3.045
1989 3.168
1990 3.306
1991 3.428
1992 3.49
1993 3.463
1994 3.36
1995 3.219
1996 3.087
1997 2.993
1998 2.955
1999 2.968
2000 3.004
2001 3.033
2002 3.041
2003 3.023
2004 2.979
2005 2.925
2006 2.876
2007 2.839
2008 2.816
2009 2.808
2010 2.805
2011 2.8
2012 2.794
2013 2.786
2014 2.778
2015 2.768
2016 2.758
2017 2.744
2018 2.725
2019 2.7
2020 2.673
2021 2.645
2022 2.618
2023 2.591
2024 2.566
2025 2.54
2026 2.515
2027 2.488
2028 2.462
2029 2.435
2030 2.408
2031 2.381
2032 2.354
2033 2.326
2034 2.299
2035 2.272
2036 2.245
2037 2.217
2038 2.189
2039 2.161
2040 2.132
2041 2.103
2042 2.074
2043 2.045
2044 2.017
2045 1.988
2046 1.96
2047 1.931
2048 1.904
2049 1.877
2050 1.85
2051 1.823
2052 1.797
2053 1.77
2054 1.743
2055 1.716
2056 1.69
2057 1.663
2058 1.638
2059 1.613
2060 1.589
2061 1.565
2062 1.54
2063 1.515
2064 1.489
2065 1.463
2066 1.437
2067 1.412
2068 1.387
2069 1.362
2070 1.337
2071 1.313
2072 1.289
2073 1.264
2074 1.24
2075 1.216
2076 1.191
2077 1.168
2078 1.144
2079 1.122
2080 1.099
2081 1.077
2082 1.055
2083 1.033
2084 1.011
2085 0.989
2086 0.967
2087 0.945
2088 0.924
2089 0.902
2090 0.88
2091 0.858
2092 0.837
2093 0.817
2094 0.796
2095 0.776
2096 0.757
2097 0.738
2098 0.719
2099 0.7