Year Percent
1950 1.479
1951 1.529
1952 1.616
1953 1.682
1954 1.733
1955 1.776
1956 1.815
1957 1.855
1958 1.9
1959 1.95
1960 2.002
1961 2.052
1962 2.093
1963 2.12
1964 2.135
1965 2.146
1966 2.162
1967 2.186
1968 2.219
1969 2.261
1970 2.302
1971 2.339
1972 2.398
1973 2.503
1974 2.643
1975 2.8
1976 2.943
1977 3.025
1978 3.013
1979 2.92
1980 2.786
1981 2.659
1982 2.569
1983 2.532
1984 2.546
1985 2.583
1986 2.614
1987 2.628
1988 2.622
1989 2.596
1990 2.562
1991 2.533
1992 2.512
1993 2.498
1994 2.491
1995 2.489
1996 2.488
1997 2.489
1998 2.493
1999 2.5
2000 2.507
2001 2.516
2002 2.529
2003 2.548
2004 2.572
2005 2.598
2006 2.621
2007 2.64
2008 2.655
2009 2.665
2010 2.672
2011 2.676
2012 2.675
2013 2.666
2014 2.65
2015 2.63
2016 2.609
2017 2.589
2018 2.572
2019 2.557
2020 2.543
2021 2.528
2022 2.514
2023 2.5
2024 2.488
2025 2.476
2026 2.463
2027 2.451
2028 2.438
2029 2.425
2030 2.411
2031 2.397
2032 2.381
2033 2.365
2034 2.347
2035 2.329
2036 2.309
2037 2.289
2038 2.267
2039 2.244
2040 2.22
2041 2.196
2042 2.171
2043 2.145
2044 2.118
2045 2.092
2046 2.064
2047 2.037
2048 2.01
2049 1.983
2050 1.957
2051 1.93
2052 1.903
2053 1.875
2054 1.848
2055 1.82
2056 1.792
2057 1.765
2058 1.739
2059 1.713
2060 1.688
2061 1.663
2062 1.638
2063 1.613
2064 1.589
2065 1.565
2066 1.54
2067 1.516
2068 1.491
2069 1.465
2070 1.44
2071 1.414
2072 1.388
2073 1.362
2074 1.336
2075 1.309
2076 1.283
2077 1.257
2078 1.232
2079 1.207
2080 1.182
2081 1.157
2082 1.133
2083 1.109
2084 1.086
2085 1.062
2086 1.039
2087 1.016
2088 0.993
2089 0.97
2090 0.946
2091 0.923
2092 0.901
2093 0.878
2094 0.856
2095 0.834
2096 0.813
2097 0.791
2098 0.77
2099 0.748