Year Percent
1950 2.005
1951 2.04
1952 2.106
1953 2.164
1954 2.216
1955 2.266
1956 2.315
1957 2.365
1958 2.418
1959 2.474
1960 2.531
1961 2.587
1962 2.637
1963 2.679
1964 2.714
1965 2.743
1966 2.767
1967 2.8
1968 2.851
1969 2.915
1970 2.984
1971 3.045
1972 3.081
1973 3.08
1974 3.047
1975 2.996
1976 2.946
1977 2.91
1978 2.897
1979 2.904
1980 2.922
1981 2.936
1982 2.934
1983 2.91
1984 2.868
1985 2.818
1986 2.774
1987 2.741
1988 2.723
1989 2.718
1990 2.72
1991 2.723
1992 2.73
1993 2.745
1994 2.768
1995 2.799
1996 2.834
1997 2.856
1998 2.852
1999 2.826
2000 2.782
2001 2.736
2002 2.739
2003 2.828
2004 2.988
2005 3.182
2006 3.354
2007 3.433
2008 3.373
2009 3.192
2010 2.956
2011 2.735
2012 2.577
2013 2.502
2014 2.506
2015 2.549
2016 2.585
2017 2.604
2018 2.606
2019 2.589
2020 2.566
2021 2.548
2022 2.535
2023 2.528
2024 2.525
2025 2.523
2026 2.519
2027 2.515
2028 2.509
2029 2.502
2030 2.493
2031 2.483
2032 2.471
2033 2.455
2034 2.435
2035 2.413
2036 2.391
2037 2.366
2038 2.338
2039 2.307
2040 2.275
2041 2.243
2042 2.211
2043 2.18
2044 2.149
2045 2.119
2046 2.089
2047 2.061
2048 2.034
2049 2.009
2050 1.986
2051 1.962
2052 1.94
2053 1.918
2054 1.896
2055 1.875
2056 1.855
2057 1.834
2058 1.814
2059 1.794
2060 1.774
2061 1.755
2062 1.734
2063 1.713
2064 1.691
2065 1.668
2066 1.646
2067 1.623
2068 1.6
2069 1.576
2070 1.552
2071 1.528
2072 1.504
2073 1.481
2074 1.457
2075 1.434
2076 1.411
2077 1.387
2078 1.364
2079 1.341
2080 1.317
2081 1.294
2082 1.271
2083 1.249
2084 1.227
2085 1.206
2086 1.184
2087 1.163
2088 1.141
2089 1.118
2090 1.095
2091 1.072
2092 1.05
2093 1.028
2094 1.007
2095 0.986
2096 0.965
2097 0.945
2098 0.924
2099 0.903