Year Percent
1950 2.363
1951 2.353
1952 2.334
1953 2.32
1954 2.309
1955 2.301
1956 2.297
1957 2.294
1958 2.295
1959 2.297
1960 2.302
1961 2.309
1962 2.318
1963 2.331
1964 2.347
1965 2.351
1966 2.343
1967 2.355
1968 2.414
1969 2.509
1970 2.636
1971 2.757
1972 2.764
1973 2.575
1974 2.216
1975 1.774
1976 1.362
1977 1.115
1978 1.127
1979 1.39
1980 1.777
1981 2.149
1982 2.446
1983 2.65
1984 2.758
1985 2.814
1986 2.862
1987 2.896
1988 2.901
1989 2.878
1990 2.838
1991 2.785
1992 2.702
1993 2.576
1994 2.414
1995 2.236
1996 2.065
1997 1.915
1998 1.794
1999 1.704
2000 1.626
2001 1.552
2002 1.502
2003 1.499
2004 1.539
2005 1.605
2006 1.673
2007 1.704
2008 1.671
2009 1.578
2010 1.453
2011 1.334
2012 1.256
2013 1.241
2014 1.288
2015 1.365
2016 1.436
2017 1.479
2018 1.48
2019 1.441
2020 1.383
2021 1.325
2022 1.274
2023 1.23
2024 1.194
2025 1.16
2026 1.124
2027 1.087
2028 1.05
2029 1.015
2030 0.98
2031 0.945
2032 0.91
2033 0.876
2034 0.843
2035 0.809
2036 0.776
2037 0.743
2038 0.71
2039 0.678
2040 0.645
2041 0.613
2042 0.582
2043 0.549
2044 0.517
2045 0.485
2046 0.453
2047 0.422
2048 0.392
2049 0.362
2050 0.333
2051 0.304
2052 0.275
2053 0.247
2054 0.218
2055 0.19
2056 0.162
2057 0.135
2058 0.108
2059 0.081
2060 0.054
2061 0.028
2062 0.002
2063 -0.023
2064 -0.048
2065 -0.073
2066 -0.097
2067 -0.121
2068 -0.145
2069 -0.167
2070 -0.19
2071 -0.211
2072 -0.232
2073 -0.252
2074 -0.272
2075 -0.29
2076 -0.308
2077 -0.325
2078 -0.342
2079 -0.357
2080 -0.371
2081 -0.385
2082 -0.398
2083 -0.41
2084 -0.421
2085 -0.431
2086 -0.441
2087 -0.45
2088 -0.459
2089 -0.468
2090 -0.477
2091 -0.485
2092 -0.493
2093 -0.501
2094 -0.508
2095 -0.515
2096 -0.521
2097 -0.528
2098 -0.535
2099 -0.542