Year Percent
1950 0.815
1951 0.866
1952 0.971
1953 1.081
1954 1.193
1955 1.301
1956 1.404
1957 1.497
1958 1.577
1959 1.643
1960 1.694
1961 1.729
1962 1.748
1963 1.752
1964 1.738
1965 1.718
1966 1.689
1967 1.62
1968 1.485
1969 1.29
1970 1.064
1971 0.844
1972 0.668
1973 0.563
1974 0.531
1975 0.537
1976 0.547
1977 0.561
1978 0.588
1979 0.625
1980 0.654
1981 0.67
1982 0.699
1983 0.767
1984 0.862
1985 0.984
1986 1.099
1987 1.071
1988 0.791
1989 0.273
1990 -0.385
1991 -1.049
1992 -1.57
1993 -1.83
1994 -1.805
1995 -1.613
1996 -1.402
1997 -1.232
1998 -1.12
1999 -1.08
2000 -1.069
2001 -1.04
2002 -1.006
2003 -1
2004 -1.021
2005 -1.053
2006 -1.082
2007 -1.121
2008 -1.185
2009 -1.27
2010 -1.377
2011 -1.486
2012 -1.526
2013 -1.424
2014 -1.18
2015 -0.845
2016 -0.502
2017 -0.233
2018 -0.101
2019 -0.11
2020 -0.199
2021 -0.291
2022 -0.361
2023 -0.402
2024 -0.41
2025 -0.406
2026 -0.411
2027 -0.423
2028 -0.434
2029 -0.442
2030 -0.449
2031 -0.455
2032 -0.461
2033 -0.465
2034 -0.467
2035 -0.469
2036 -0.471
2037 -0.473
2038 -0.475
2039 -0.479
2040 -0.483
2041 -0.487
2042 -0.493
2043 -0.501
2044 -0.512
2045 -0.524
2046 -0.536
2047 -0.548
2048 -0.559
2049 -0.57
2050 -0.58
2051 -0.59
2052 -0.599
2053 -0.607
2054 -0.615
2055 -0.621
2056 -0.627
2057 -0.632
2058 -0.635
2059 -0.636
2060 -0.637
2061 -0.637
2062 -0.636
2063 -0.633
2064 -0.63
2065 -0.626
2066 -0.621
2067 -0.616
2068 -0.611
2069 -0.606
2070 -0.602
2071 -0.597
2072 -0.592
2073 -0.588
2074 -0.583
2075 -0.579
2076 -0.575
2077 -0.571
2078 -0.567
2079 -0.563
2080 -0.558
2081 -0.555
2082 -0.551
2083 -0.547
2084 -0.544
2085 -0.541
2086 -0.537
2087 -0.535
2088 -0.532
2089 -0.53
2090 -0.528
2091 -0.527
2092 -0.527
2093 -0.527
2094 -0.529
2095 -0.531
2096 -0.534
2097 -0.539
2098 -0.544
2099 -0.551