Year Percent
1950 2.36
1951 2.375
1952 2.404
1953 2.429
1954 2.452
1955 2.474
1956 2.498
1957 2.522
1958 2.549
1959 2.578
1960 2.608
1961 2.635
1962 2.658
1963 2.675
1964 2.686
1965 2.691
1966 2.693
1967 2.699
1968 2.714
1969 2.738
1970 2.764
1971 2.786
1972 2.789
1973 2.762
1974 2.71
1975 2.642
1976 2.574
1977 2.525
1978 2.508
1979 2.519
1980 2.546
1981 2.57
1982 2.564
1983 2.511
1984 2.415
1985 2.294
1986 2.176
1987 2.101
1988 2.099
1989 2.163
1990 2.258
1991 2.34
1992 2.366
1993 2.307
1994 2.171
1995 1.997
1996 1.83
1997 1.689
1998 1.58
1999 1.505
2000 1.45
2001 1.399
2002 1.344
2003 1.282
2004 1.215
2005 1.145
2006 1.081
2007 1.05
2008 1.074
2009 1.15
2010 1.252
2011 1.352
2012 1.418
2013 1.433
2014 1.397
2015 1.335
2016 1.273
2017 1.219
2018 1.174
2019 1.139
2020 1.108
2021 1.074
2022 1.037
2023 1.001
2024 0.964
2025 0.927
2026 0.891
2027 0.859
2028 0.83
2029 0.806
2030 0.785
2031 0.764
2032 0.745
2033 0.725
2034 0.707
2035 0.689
2036 0.671
2037 0.655
2038 0.638
2039 0.621
2040 0.604
2041 0.588
2042 0.571
2043 0.554
2044 0.537
2045 0.519
2046 0.501
2047 0.484
2048 0.467
2049 0.45
2050 0.433
2051 0.417
2052 0.4
2053 0.384
2054 0.368
2055 0.352
2056 0.336
2057 0.32
2058 0.306
2059 0.291
2060 0.277
2061 0.263
2062 0.25
2063 0.236
2064 0.222
2065 0.209
2066 0.196
2067 0.183
2068 0.17
2069 0.156
2070 0.143
2071 0.13
2072 0.117
2073 0.105
2074 0.093
2075 0.081
2076 0.069
2077 0.058
2078 0.046
2079 0.035
2080 0.024
2081 0.013
2082 0.002
2083 -0.008
2084 -0.019
2085 -0.029
2086 -0.038
2087 -0.048
2088 -0.057
2089 -0.066
2090 -0.075
2091 -0.084
2092 -0.092
2093 -0.1
2094 -0.109
2095 -0.117
2096 -0.124
2097 -0.132
2098 -0.139
2099 -0.147