Year Percent
1950 1.852
1951 1.872
1952 1.905
1953 1.929
1954 1.95
1955 1.974
1956 2.007
1957 2.054
1958 2.116
1959 2.192
1960 2.277
1961 2.359
1962 2.426
1963 2.469
1964 2.49
1965 2.487
1966 2.472
1967 2.482
1968 2.546
1969 2.654
1970 2.797
1971 2.934
1972 2.954
1973 2.774
1974 2.425
1975 1.993
1976 1.595
1977 1.371
1978 1.419
1979 1.726
1980 2.164
1981 2.586
1982 2.911
1983 3.108
1984 3.18
1985 3.188
1986 3.196
1987 3.231
1988 3.298
1989 3.393
1990 3.493
1991 3.572
1992 3.593
1993 3.535
1994 3.409
1995 3.251
1996 3.101
1997 2.985
1998 2.917
1999 2.895
2000 2.894
2001 2.89
2002 2.874
2003 2.845
2004 2.802
2005 2.754
2006 2.71
2007 2.675
2008 2.654
2009 2.644
2010 2.64
2011 2.633
2012 2.618
2013 2.594
2014 2.56
2015 2.522
2016 2.483
2017 2.445
2018 2.408
2019 2.372
2020 2.336
2021 2.299
2022 2.261
2023 2.221
2024 2.179
2025 2.137
2026 2.095
2027 2.054
2028 2.013
2029 1.973
2030 1.933
2031 1.894
2032 1.855
2033 1.815
2034 1.776
2035 1.737
2036 1.698
2037 1.66
2038 1.624
2039 1.589
2040 1.555
2041 1.521
2042 1.488
2043 1.454
2044 1.42
2045 1.387
2046 1.354
2047 1.321
2048 1.288
2049 1.255
2050 1.222
2051 1.19
2052 1.158
2053 1.126
2054 1.094
2055 1.062
2056 1.031
2057 1
2058 0.969
2059 0.938
2060 0.908
2061 0.878
2062 0.848
2063 0.819
2064 0.79
2065 0.761
2066 0.733
2067 0.704
2068 0.677
2069 0.65
2070 0.623
2071 0.596
2072 0.57
2073 0.544
2074 0.518
2075 0.493
2076 0.468
2077 0.443
2078 0.419
2079 0.396
2080 0.374
2081 0.351
2082 0.329
2083 0.308
2084 0.286
2085 0.265
2086 0.245
2087 0.225
2088 0.206
2089 0.188
2090 0.17
2091 0.153
2092 0.137
2093 0.121
2094 0.105
2095 0.09
2096 0.076
2097 0.062
2098 0.048
2099 0.036