Year Percent
1950 1.688
1951 1.602
1952 1.471
1953 1.408
1954 1.387
1955 1.381
1956 1.367
1957 1.325
1958 1.242
1959 1.117
1960 0.967
1961 0.826
1962 0.739
1963 0.742
1964 0.832
1965 0.967
1966 1.1
1967 1.195
1968 1.233
1969 1.214
1970 1.164
1971 1.114
1972 1.07
1973 1.035
1974 1.007
1975 0.984
1976 0.956
1977 0.91
1978 0.838
1979 0.741
1980 0.626
1981 0.507
1982 0.414
1983 0.373
1984 0.38
1985 0.416
1986 0.449
1987 0.436
1988 0.343
1989 0.173
1990 -0.039
1991 -0.248
1992 -0.424
1993 -0.553
1994 -0.629
1995 -0.679
1996 -0.729
1997 -0.765
1998 -0.767
1999 -0.74
2000 -0.686
2001 -0.622
2002 -0.584
2003 -0.607
2004 -0.69
2005 -0.811
2006 -0.93
2007 -1.005
2008 -1.004
2009 -0.923
2010 -0.794
2011 -0.663
2012 -0.557
2013 -0.495
2014 -0.48
2015 -0.49
2016 -0.499
2017 -0.502
2018 -0.5
2019 -0.493
2020 -0.486
2021 -0.482
2022 -0.481
2023 -0.481
2024 -0.482
2025 -0.484
2026 -0.486
2027 -0.49
2028 -0.497
2029 -0.505
2030 -0.515
2031 -0.525
2032 -0.535
2033 -0.544
2034 -0.551
2035 -0.558
2036 -0.565
2037 -0.572
2038 -0.58
2039 -0.588
2040 -0.595
2041 -0.603
2042 -0.611
2043 -0.618
2044 -0.624
2045 -0.631
2046 -0.637
2047 -0.643
2048 -0.649
2049 -0.654
2050 -0.659
2051 -0.664
2052 -0.669
2053 -0.675
2054 -0.682
2055 -0.689
2056 -0.695
2057 -0.701
2058 -0.706
2059 -0.711
2060 -0.715
2061 -0.718
2062 -0.72
2063 -0.72
2064 -0.717
2065 -0.714
2066 -0.709
2067 -0.703
2068 -0.696
2069 -0.688
2070 -0.678
2071 -0.668
2072 -0.658
2073 -0.648
2074 -0.639
2075 -0.63
2076 -0.621
2077 -0.611
2078 -0.602
2079 -0.592
2080 -0.583
2081 -0.573
2082 -0.564
2083 -0.556
2084 -0.548
2085 -0.541
2086 -0.534
2087 -0.528
2088 -0.521
2089 -0.514
2090 -0.507
2091 -0.5
2092 -0.494
2093 -0.489
2094 -0.486
2095 -0.482
2096 -0.48
2097 -0.478
2098 -0.477
2099 -0.476