Year Percent
1950 1.907
1951 1.903
1952 1.902
1953 1.912
1954 1.93
1955 1.954
1956 1.979
1957 2.006
1958 2.031
1959 2.055
1960 2.077
1961 2.1
1962 2.128
1963 2.161
1964 2.198
1965 2.323
1966 2.542
1967 2.632
1968 2.406
1969 1.935
1970 1.206
1971 0.44
1972 0.512
1973 2.147
1974 5.072
1975 8.381
1976 10.919
1977 11.676
1978 10.485
1979 8.011
1980 5.19
1981 2.733
1982 1.014
1983 0.234
1984 0.381
1985 1.023
1986 1.64
1987 1.978
1988 1.958
1989 1.594
1990 1.068
1991 0.613
1992 0.427
1993 0.633
1994 1.216
1995 1.993
1996 2.731
1997 3.25
1998 3.458
1999 3.38
2000 3.169
2001 2.976
2002 2.853
2003 2.806
2004 2.834
2005 2.891
2006 2.932
2007 2.948
2008 2.944
2009 2.921
2010 2.89
2011 2.864
2012 2.85
2013 2.853
2014 2.87
2015 2.893
2016 2.913
2017 2.929
2018 2.943
2019 2.952
2020 2.958
2021 2.962
2022 2.961
2023 2.952
2024 2.936
2025 2.915
2026 2.893
2027 2.871
2028 2.848
2029 2.826
2030 2.804
2031 2.78
2032 2.755
2033 2.73
2034 2.704
2035 2.678
2036 2.651
2037 2.625
2038 2.599
2039 2.574
2040 2.548
2041 2.523
2042 2.497
2043 2.472
2044 2.447
2045 2.421
2046 2.395
2047 2.369
2048 2.342
2049 2.314
2050 2.286
2051 2.258
2052 2.229
2053 2.2
2054 2.171
2055 2.141
2056 2.112
2057 2.082
2058 2.052
2059 2.022
2060 1.991
2061 1.961
2062 1.931
2063 1.901
2064 1.872
2065 1.844
2066 1.815
2067 1.787
2068 1.759
2069 1.731
2070 1.703
2071 1.675
2072 1.648
2073 1.62
2074 1.593
2075 1.566
2076 1.538
2077 1.511
2078 1.484
2079 1.457
2080 1.43
2081 1.403
2082 1.377
2083 1.351
2084 1.325
2085 1.299
2086 1.274
2087 1.248
2088 1.222
2089 1.196
2090 1.17
2091 1.144
2092 1.118
2093 1.093
2094 1.069
2095 1.045
2096 1.021
2097 0.998
2098 0.975
2099 0.952