Year Percent
1950 2.129
1951 1.637
1952 0.924
1953 0.676
1954 0.743
1955 0.989
1956 1.279
1957 1.495
1958 1.551
1959 1.429
1960 1.199
1961 1.01
1962 1.06
1963 1.506
1964 2.302
1965 3.259
1966 4.122
1967 4.62
1968 4.616
1969 4.182
1970 3.573
1971 3.028
1972 2.622
1973 2.369
1974 2.272
1975 2.237
1976 2.194
1977 2.222
1978 2.408
1979 2.726
1980 3.103
1981 3.448
1982 3.671
1983 3.72
1984 3.613
1985 3.442
1986 3.288
1987 3.138
1988 2.966
1989 2.783
1990 2.589
1991 2.402
1992 2.299
1993 2.339
1994 2.508
1995 2.741
1996 2.959
1997 3.094
1998 3.112
1999 3.02
2000 2.879
2001 2.751
2002 2.663
2003 2.626
2004 2.636
2005 2.667
2006 2.69
2007 2.701
2008 2.703
2009 2.694
2010 2.682
2011 2.669
2012 2.651
2013 2.623
2014 2.586
2015 2.545
2016 2.504
2017 2.466
2018 2.432
2019 2.403
2020 2.375
2021 2.348
2022 2.321
2023 2.297
2024 2.276
2025 2.255
2026 2.235
2027 2.214
2028 2.193
2029 2.17
2030 2.148
2031 2.125
2032 2.101
2033 2.076
2034 2.05
2035 2.024
2036 1.996
2037 1.969
2038 1.941
2039 1.912
2040 1.883
2041 1.854
2042 1.825
2043 1.795
2044 1.765
2045 1.734
2046 1.704
2047 1.674
2048 1.646
2049 1.62
2050 1.594
2051 1.568
2052 1.542
2053 1.516
2054 1.49
2055 1.464
2056 1.438
2057 1.413
2058 1.389
2059 1.365
2060 1.342
2061 1.32
2062 1.297
2063 1.274
2064 1.25
2065 1.227
2066 1.204
2067 1.18
2068 1.157
2069 1.133
2070 1.11
2071 1.086
2072 1.063
2073 1.039
2074 1.016
2075 0.992
2076 0.969
2077 0.946
2078 0.923
2079 0.9
2080 0.877
2081 0.854
2082 0.832
2083 0.809
2084 0.786
2085 0.763
2086 0.74
2087 0.718
2088 0.696
2089 0.676
2090 0.656
2091 0.636
2092 0.617
2093 0.598
2094 0.578
2095 0.56
2096 0.541
2097 0.523
2098 0.506
2099 0.489