Year Percent
1950 4.409
1951 3.946
1952 3.217
1953 2.823
1954 2.664
1955 2.655
1956 2.722
1957 2.808
1958 2.869
1959 2.884
1960 2.865
1961 2.856
1962 2.906
1963 3.051
1964 3.264
1965 3.513
1966 3.724
1967 3.731
1968 3.414
1969 2.82
1970 2.105
1971 1.435
1972 0.926
1973 0.649
1974 0.609
1975 0.687
1976 0.769
1977 0.869
1978 1.027
1979 1.228
1980 1.462
1981 1.707
1982 1.895
1983 1.971
1984 1.943
1985 1.86
1986 1.779
1987 1.733
1988 1.741
1989 1.801
1990 1.88
1991 1.944
1992 1.982
1993 1.99
1994 1.965
1995 1.923
1996 1.876
1997 1.826
1998 1.769
1999 1.706
2000 1.641
2001 1.573
2002 1.495
2003 1.401
2004 1.293
2005 1.18
2006 1.071
2007 0.977
2008 0.907
2009 0.861
2010 0.829
2011 0.8
2012 0.776
2013 0.762
2014 0.756
2015 0.756
2016 0.759
2017 0.76
2018 0.756
2019 0.747
2020 0.734
2021 0.722
2022 0.709
2023 0.694
2024 0.676
2025 0.657
2026 0.637
2027 0.616
2028 0.595
2029 0.574
2030 0.553
2031 0.532
2032 0.508
2033 0.483
2034 0.457
2035 0.429
2036 0.402
2037 0.374
2038 0.344
2039 0.315
2040 0.286
2041 0.257
2042 0.228
2043 0.199
2044 0.171
2045 0.144
2046 0.117
2047 0.092
2048 0.069
2049 0.048
2050 0.028
2051 0.009
2052 -0.009
2053 -0.024
2054 -0.038
2055 -0.05
2056 -0.06
2057 -0.07
2058 -0.079
2059 -0.086
2060 -0.091
2061 -0.097
2062 -0.101
2063 -0.104
2064 -0.105
2065 -0.106
2066 -0.107
2067 -0.107
2068 -0.108
2069 -0.108
2070 -0.109
2071 -0.109
2072 -0.111
2073 -0.113
2074 -0.116
2075 -0.12
2076 -0.125
2077 -0.13
2078 -0.136
2079 -0.143
2080 -0.149
2081 -0.158
2082 -0.166
2083 -0.175
2084 -0.186
2085 -0.197
2086 -0.208
2087 -0.22
2088 -0.231
2089 -0.244
2090 -0.256
2091 -0.267
2092 -0.279
2093 -0.29
2094 -0.301
2095 -0.31
2096 -0.32
2097 -0.328
2098 -0.336
2099 -0.342