Year Percent
1950 2.074
1951 2.337
1952 2.799
1953 3.139
1954 3.376
1955 3.528
1956 3.614
1957 3.649
1958 3.648
1959 3.618
1960 3.564
1961 3.488
1962 3.387
1963 3.262
1964 3.119
1965 2.965
1966 2.809
1967 2.676
1968 2.579
1969 2.516
1970 2.471
1971 2.424
1972 2.36
1973 2.273
1974 2.164
1975 2.046
1976 1.932
1977 1.832
1978 1.748
1979 1.679
1980 1.597
1981 1.493
1982 1.417
1983 1.419
1984 1.481
1985 1.597
1986 1.709
1987 1.63
1988 1.21
1989 0.476
1990 -0.443
1991 -1.366
1992 -2.07
1993 -2.366
1994 -2.215
1995 -1.79
1996 -1.327
1997 -0.948
1998 -0.708
1999 -0.633
2000 -0.625
2001 -0.585
2002 -0.541
2003 -0.552
2004 -0.609
2005 -0.707
2006 -0.815
2007 -0.857
2008 -0.764
2009 -0.534
2010 -0.226
2011 0.08
2012 0.311
2013 0.42
2014 0.403
2015 0.319
2016 0.231
2017 0.159
2018 0.107
2019 0.077
2020 0.055
2021 0.024
2022 -0.013
2023 -0.049
2024 -0.082
2025 -0.113
2026 -0.144
2027 -0.173
2028 -0.2
2029 -0.223
2030 -0.244
2031 -0.264
2032 -0.282
2033 -0.296
2034 -0.307
2035 -0.316
2036 -0.324
2037 -0.332
2038 -0.34
2039 -0.349
2040 -0.357
2041 -0.366
2042 -0.376
2043 -0.39
2044 -0.406
2045 -0.424
2046 -0.443
2047 -0.462
2048 -0.481
2049 -0.501
2050 -0.521
2051 -0.541
2052 -0.561
2053 -0.58
2054 -0.599
2055 -0.616
2056 -0.633
2057 -0.649
2058 -0.664
2059 -0.678
2060 -0.691
2061 -0.704
2062 -0.715
2063 -0.726
2064 -0.735
2065 -0.744
2066 -0.753
2067 -0.761
2068 -0.769
2069 -0.778
2070 -0.787
2071 -0.795
2072 -0.803
2073 -0.811
2074 -0.819
2075 -0.826
2076 -0.832
2077 -0.838
2078 -0.843
2079 -0.847
2080 -0.849
2081 -0.851
2082 -0.851
2083 -0.85
2084 -0.847
2085 -0.842
2086 -0.836
2087 -0.83
2088 -0.823
2089 -0.815
2090 -0.807
2091 -0.799
2092 -0.791
2093 -0.783
2094 -0.775
2095 -0.769
2096 -0.763
2097 -0.758
2098 -0.755
2099 -0.753