Year Percent
1950 1.743
1951 2.068
1952 2.602
1953 2.928
1954 3.098
1955 3.163
1956 3.17
1957 3.155
1958 3.147
1959 3.154
1960 3.166
1961 3.154
1962 3.084
1963 2.931
1964 2.712
1965 2.452
1966 2.2
1967 2.049
1968 2.066
1969 2.236
1970 2.497
1971 2.753
1972 2.877
1973 2.787
1974 2.51
1975 2.136
1976 1.791
1977 1.625
1978 1.74
1979 2.116
1980 2.617
1981 3.079
1982 3.38
1983 3.46
1984 3.338
1985 3.122
1986 2.922
1987 2.782
1988 2.716
1989 2.718
1990 2.753
1991 2.778
1992 2.771
1993 2.725
1994 2.646
1995 2.553
1996 2.469
1997 2.416
1998 2.408
1999 2.441
2000 2.491
2001 2.537
2002 2.572
2003 2.596
2004 2.609
2005 2.615
2006 2.618
2007 2.611
2008 2.583
2009 2.539
2010 2.485
2011 2.43
2012 2.38
2013 2.334
2014 2.293
2015 2.256
2016 2.217
2017 2.18
2018 2.144
2019 2.11
2020 2.078
2021 2.047
2022 2.016
2023 1.987
2024 1.958
2025 1.93
2026 1.904
2027 1.878
2028 1.854
2029 1.832
2030 1.81
2031 1.789
2032 1.768
2033 1.747
2034 1.725
2035 1.704
2036 1.682
2037 1.661
2038 1.64
2039 1.619
2040 1.598
2041 1.577
2042 1.555
2043 1.532
2044 1.507
2045 1.481
2046 1.456
2047 1.43
2048 1.403
2049 1.375
2050 1.347
2051 1.319
2052 1.292
2053 1.265
2054 1.239
2055 1.213
2056 1.188
2057 1.163
2058 1.14
2059 1.117
2060 1.095
2061 1.073
2062 1.052
2063 1.032
2064 1.012
2065 0.992
2066 0.973
2067 0.954
2068 0.935
2069 0.915
2070 0.896
2071 0.877
2072 0.857
2073 0.838
2074 0.818
2075 0.798
2076 0.778
2077 0.759
2078 0.739
2079 0.719
2080 0.7
2081 0.68
2082 0.661
2083 0.641
2084 0.62
2085 0.6
2086 0.579
2087 0.56
2088 0.541
2089 0.523
2090 0.506
2091 0.489
2092 0.473
2093 0.456
2094 0.441
2095 0.425
2096 0.41
2097 0.396
2098 0.382
2099 0.37