Year Percent
1950 1.725
1951 1.839
1952 2.017
1953 2.128
1954 2.22
1955 2.292
1956 2.336
1957 2.363
1958 2.411
1959 2.441
1960 2.445
1961 2.448
1962 2.432
1963 2.393
1964 2.302
1965 2.19
1966 2.091
1967 1.992
1968 1.881
1969 1.78
1970 1.692
1971 1.583
1972 1.495
1973 1.452
1974 1.439
1975 1.447
1976 1.466
1977 1.483
1978 1.471
1979 1.433
1980 1.371
1981 1.315
1982 1.341
1983 1.492
1984 1.777
1985 2.146
1986 2.483
1987 2.66
1988 2.606
1989 2.342
1990 1.965
1991 1.602
1992 1.351
1993 1.256
1994 1.311
1995 1.437
1996 1.554
1997 1.647
1998 1.705
1999 1.721
2000 1.713
2001 1.71
2002 1.738
2003 1.799
2004 1.893
2005 2.012
2006 2.113
2007 2.17
2008 2.163
2009 2.095
2010 1.992
2011 1.893
2012 1.82
2013 1.771
2014 1.753
2015 1.751
2016 1.744
2017 1.726
2018 1.702
2019 1.671
2020 1.636
2021 1.597
2022 1.564
2023 1.531
2024 1.489
2025 1.451
2026 1.412
2027 1.371
2028 1.335
2029 1.299
2030 1.268
2031 1.238
2032 1.207
2033 1.191
2034 1.181
2035 1.169
2036 1.161
2037 1.158
2038 1.153
2039 1.154
2040 1.157
2041 1.155
2042 1.152
2043 1.149
2044 1.138
2045 1.122
2046 1.109
2047 1.092
2048 1.076
2049 1.057
2050 1.038
2051 1.018
2052 0.993
2053 0.97
2054 0.949
2055 0.923
2056 0.896
2057 0.874
2058 0.852
2059 0.826
2060 0.807
2061 0.784
2062 0.763
2063 0.747
2064 0.733
2065 0.719
2066 0.706
2067 0.693
2068 0.683
2069 0.677
2070 0.672
2071 0.664
2072 0.657
2073 0.651
2074 0.643
2075 0.637
2076 0.63
2077 0.62
2078 0.609
2079 0.597
2080 0.583
2081 0.566
2082 0.553
2083 0.537
2084 0.517
2085 0.498
2086 0.479
2087 0.461
2088 0.441
2089 0.424
2090 0.407
2091 0.391
2092 0.374
2093 0.358
2094 0.343
2095 0.332
2096 0.32
2097 0.306
2098 0.297
2099 0.292