Year Percent
1950 7.363
1951 7.155
1952 6.635
1953 5.976
1954 5.295
1955 4.672
1956 4.173
1957 3.842
1958 3.701
1959 3.735
1960 3.874
1961 4.008
1962 4.012
1963 3.804
1964 3.416
1965 2.946
1966 2.516
1967 2.258
1968 2.257
1969 2.488
1970 2.828
1971 3.133
1972 3.3
1973 3.279
1974 3.086
1975 2.822
1976 2.581
1977 2.376
1978 2.196
1979 2.047
1980 1.923
1981 1.82
1982 1.737
1983 1.68
1984 1.652
1985 1.627
1986 1.607
1987 1.69
1988 1.956
1989 2.376
1990 2.868
1991 3.314
1992 3.579
1993 3.583
1994 3.353
1995 3.023
1996 2.717
1997 2.463
1998 2.259
1999 2.11
2000 1.978
2001 1.841
2002 1.763
2003 1.806
2004 1.957
2005 2.166
2006 2.364
2007 2.471
2008 2.433
2009 2.263
2010 2.028
2011 1.806
2012 1.64
2013 1.549
2014 1.533
2015 1.553
2016 1.569
2017 1.568
2018 1.552
2019 1.519
2020 1.48
2021 1.445
2022 1.417
2023 1.393
2024 1.372
2025 1.354
2026 1.336
2027 1.32
2028 1.305
2029 1.292
2030 1.28
2031 1.268
2032 1.257
2033 1.245
2034 1.234
2035 1.222
2036 1.211
2037 1.199
2038 1.188
2039 1.176
2040 1.164
2041 1.151
2042 1.138
2043 1.123
2044 1.107
2045 1.09
2046 1.073
2047 1.055
2048 1.036
2049 1.017
2050 0.997
2051 0.977
2052 0.957
2053 0.937
2054 0.917
2055 0.897
2056 0.877
2057 0.858
2058 0.839
2059 0.821
2060 0.803
2061 0.786
2062 0.77
2063 0.755
2064 0.742
2065 0.729
2066 0.717
2067 0.705
2068 0.693
2069 0.681
2070 0.669
2071 0.658
2072 0.647
2073 0.636
2074 0.626
2075 0.615
2076 0.605
2077 0.594
2078 0.583
2079 0.571
2080 0.559
2081 0.547
2082 0.534
2083 0.52
2084 0.507
2085 0.492
2086 0.478
2087 0.464
2088 0.449
2089 0.435
2090 0.422
2091 0.408
2092 0.393
2093 0.379
2094 0.365
2095 0.35
2096 0.335
2097 0.321
2098 0.307
2099 0.293