Year Percent
1950 2.056
1951 2.077
1952 2.118
1953 2.155
1954 2.191
1955 2.226
1956 2.259
1957 2.292
1958 2.325
1959 2.357
1960 2.39
1961 2.422
1962 2.454
1963 2.484
1964 2.514
1965 2.542
1966 2.57
1967 2.6
1968 2.633
1969 2.669
1970 2.705
1971 2.739
1972 2.769
1973 2.794
1974 2.813
1975 2.829
1976 2.843
1977 2.855
1978 2.864
1979 2.871
1980 2.877
1981 2.884
1982 2.885
1983 2.876
1984 2.859
1985 2.838
1986 2.822
1987 2.818
1988 2.834
1989 2.866
1990 2.905
1991 2.941
1992 2.977
1993 3.017
1994 3.06
1995 3.101
1996 3.137
1997 3.157
1998 3.155
1999 3.134
2000 3.103
2001 3.07
2002 3.037
2003 3.003
2004 2.97
2005 2.938
2006 2.905
2007 2.872
2008 2.84
2009 2.808
2010 2.777
2011 2.748
2012 2.723
2013 2.707
2014 2.698
2015 2.692
2016 2.685
2017 2.675
2018 2.663
2019 2.647
2020 2.63
2021 2.611
2022 2.591
2023 2.568
2024 2.543
2025 2.516
2026 2.488
2027 2.459
2028 2.428
2029 2.396
2030 2.363
2031 2.329
2032 2.297
2033 2.264
2034 2.233
2035 2.201
2036 2.171
2037 2.141
2038 2.112
2039 2.084
2040 2.057
2041 2.03
2042 2.004
2043 1.978
2044 1.953
2045 1.928
2046 1.902
2047 1.877
2048 1.852
2049 1.827
2050 1.802
2051 1.777
2052 1.751
2053 1.725
2054 1.699
2055 1.672
2056 1.646
2057 1.619
2058 1.593
2059 1.567
2060 1.542
2061 1.516
2062 1.491
2063 1.465
2064 1.441
2065 1.416
2066 1.392
2067 1.367
2068 1.343
2069 1.319
2070 1.295
2071 1.271
2072 1.247
2073 1.224
2074 1.202
2075 1.179
2076 1.157
2077 1.135
2078 1.113
2079 1.091
2080 1.069
2081 1.047
2082 1.025
2083 1.004
2084 0.982
2085 0.961
2086 0.94
2087 0.919
2088 0.899
2089 0.879
2090 0.86
2091 0.841
2092 0.822
2093 0.803
2094 0.784
2095 0.765
2096 0.747
2097 0.728
2098 0.71
2099 0.692