Year Percent
1950 1.38
1951 1.405
1952 1.434
1953 1.428
1954 1.398
1955 1.356
1956 1.313
1957 1.278
1958 1.257
1959 1.253
1960 1.258
1961 1.258
1962 1.237
1963 1.18
1964 1.09
1965 0.981
1966 0.874
1967 0.789
1968 0.739
1969 0.725
1970 0.73
1971 0.734
1972 0.726
1973 0.698
1974 0.652
1975 0.596
1976 0.543
1977 0.498
1978 0.465
1979 0.444
1980 0.428
1981 0.409
1982 0.388
1983 0.367
1984 0.346
1985 0.322
1986 0.294
1987 0.255
1988 0.197
1989 0.121
1990 0.038
1991 -0.046
1992 -0.141
1993 -0.261
1994 -0.403
1995 -0.557
1996 -0.709
1997 -0.831
1998 -0.903
1999 -0.922
2000 -0.909
2001 -0.889
2002 -0.857
2003 -0.802
2004 -0.729
2005 -0.639
2006 -0.542
2007 -0.463
2008 -0.425
2009 -0.428
2010 -0.456
2011 -0.486
2012 -0.508
2013 -0.516
2014 -0.51
2015 -0.498
2016 -0.489
2017 -0.486
2018 -0.486
2019 -0.491
2020 -0.498
2021 -0.506
2022 -0.515
2023 -0.528
2024 -0.543
2025 -0.56
2026 -0.577
2027 -0.594
2028 -0.608
2029 -0.619
2030 -0.629
2031 -0.638
2032 -0.645
2033 -0.648
2034 -0.647
2035 -0.643
2036 -0.639
2037 -0.634
2038 -0.628
2039 -0.622
2040 -0.616
2041 -0.609
2042 -0.602
2043 -0.598
2044 -0.595
2045 -0.593
2046 -0.592
2047 -0.592
2048 -0.593
2049 -0.596
2050 -0.6
2051 -0.605
2052 -0.61
2053 -0.616
2054 -0.623
2055 -0.63
2056 -0.637
2057 -0.644
2058 -0.651
2059 -0.657
2060 -0.663
2061 -0.669
2062 -0.672
2063 -0.674
2064 -0.674
2065 -0.672
2066 -0.669
2067 -0.663
2068 -0.655
2069 -0.645
2070 -0.632
2071 -0.618
2072 -0.603
2073 -0.586
2074 -0.569
2075 -0.55
2076 -0.531
2077 -0.511
2078 -0.491
2079 -0.472
2080 -0.453
2081 -0.434
2082 -0.417
2083 -0.401
2084 -0.386
2085 -0.373
2086 -0.361
2087 -0.351
2088 -0.343
2089 -0.338
2090 -0.335
2091 -0.333
2092 -0.332
2093 -0.333
2094 -0.333
2095 -0.335
2096 -0.338
2097 -0.343
2098 -0.349
2099 -0.357