Year Percent
1950 2.13
1951 2.413
1952 2.577
1953 2.135
1954 1.47
1955 0.856
1956 0.624
1957 1.052
1958 2.251
1959 4.158
1960 6.377
1961 8.24
1962 9.165
1963 8.946
1964 7.889
1965 6.54
1966 5.362
1967 4.678
1968 4.611
1969 5.076
1970 5.728
1971 6.202
1972 6.291
1973 5.916
1974 5.165
1975 4.28
1976 3.472
1977 2.827
1978 2.36
1979 2.063
1980 1.872
1981 1.684
1982 1.441
1983 1.108
1984 0.698
1985 0.247
1986 -0.186
1987 -0.468
1988 -0.495
1989 -0.266
1990 0.112
1991 0.498
1992 0.779
1993 0.876
1994 0.783
1995 0.599
1996 0.426
1997 0.289
1998 0.171
1999 0.076
2000 0.004
2001 -0.076
2002 -0.156
2003 -0.217
2004 -0.259
2005 -0.285
2006 -0.303
2007 -0.315
2008 -0.315
2009 -0.305
2010 -0.295
2011 -0.28
2012 -0.252
2013 -0.212
2014 -0.159
2015 -0.094
2016 -0.036
2017 0
2018 0.004
2019 -0.027
2020 -0.083
2021 -0.141
2022 -0.194
2023 -0.239
2024 -0.264
2025 -0.287
2026 -0.317
2027 -0.348
2028 -0.373
2029 -0.405
2030 -0.435
2031 -0.457
2032 -0.487
2033 -0.513
2034 -0.537
2035 -0.569
2036 -0.598
2037 -0.624
2038 -0.646
2039 -0.671
2040 -0.694
2041 -0.716
2042 -0.739
2043 -0.756
2044 -0.782
2045 -0.805
2046 -0.826
2047 -0.846
2048 -0.86
2049 -0.872
2050 -0.875
2051 -0.88
2052 -0.883
2053 -0.883
2054 -0.89
2055 -0.89
2056 -0.887
2057 -0.889
2058 -0.879
2059 -0.873
2060 -0.874
2061 -0.869
2062 -0.863
2063 -0.857
2064 -0.849
2065 -0.846
2066 -0.837
2067 -0.835
2068 -0.834
2069 -0.825
2070 -0.826
2071 -0.826
2072 -0.825
2073 -0.824
2074 -0.831
2075 -0.836
2076 -0.84
2077 -0.851
2078 -0.861
2079 -0.877
2080 -0.897
2081 -0.905
2082 -0.911
2083 -0.934
2084 -0.956
2085 -0.97
2086 -0.986
2087 -0.998
2088 -1.016
2089 -1.032
2090 -1.052
2091 -1.079
2092 -1.096
2093 -1.104
2094 -1.115
2095 -1.134
2096 -1.141
2097 -1.144
2098 -1.154
2099 -1.161