Year Percent
1950 2.282
1951 2.173
1952 1.987
1953 1.86
1954 1.78
1955 1.732
1956 1.702
1957 1.675
1958 1.65
1959 1.616
1960 1.581
1961 1.565
1962 1.58
1963 1.635
1964 1.729
1965 1.861
1966 2.002
1967 2.106
1968 2.137
1969 2.104
1970 2.026
1971 1.957
1972 1.998
1973 2.222
1974 2.609
1975 3.072
1976 3.492
1977 3.744
1978 3.76
1979 3.567
1980 3.279
1981 3.013
1982 2.829
1983 2.755
1984 2.783
1985 2.854
1986 2.913
1987 2.947
1988 2.961
1989 2.956
1990 2.944
1991 2.932
1992 2.91
1993 2.875
1994 2.826
1995 2.772
1996 2.718
1997 2.666
1998 2.61
1999 2.551
2000 2.493
2001 2.44
2002 2.399
2003 2.379
2004 2.379
2005 2.387
2006 2.394
2007 2.4
2008 2.406
2009 2.411
2010 2.415
2011 2.418
2012 2.413
2013 2.395
2014 2.366
2015 2.329
2016 2.293
2017 2.258
2018 2.223
2019 2.189
2020 2.156
2021 2.122
2022 2.089
2023 2.057
2024 2.025
2025 1.993
2026 1.963
2027 1.933
2028 1.905
2029 1.878
2030 1.851
2031 1.826
2032 1.8
2033 1.775
2034 1.751
2035 1.727
2036 1.702
2037 1.679
2038 1.655
2039 1.63
2040 1.605
2041 1.58
2042 1.555
2043 1.53
2044 1.503
2045 1.477
2046 1.451
2047 1.424
2048 1.398
2049 1.371
2050 1.344
2051 1.317
2052 1.291
2053 1.265
2054 1.24
2055 1.214
2056 1.19
2057 1.165
2058 1.14
2059 1.116
2060 1.092
2061 1.069
2062 1.045
2063 1.023
2064 1.002
2065 0.981
2066 0.96
2067 0.939
2068 0.918
2069 0.896
2070 0.874
2071 0.852
2072 0.83
2073 0.808
2074 0.787
2075 0.765
2076 0.744
2077 0.723
2078 0.702
2079 0.681
2080 0.661
2081 0.641
2082 0.621
2083 0.6
2084 0.58
2085 0.559
2086 0.539
2087 0.52
2088 0.501
2089 0.482
2090 0.464
2091 0.447
2092 0.429
2093 0.412
2094 0.395
2095 0.378
2096 0.362
2097 0.346
2098 0.33
2099 0.316