Year Percent
1950 2.271
1951 1.81
1952 1.107
1953 0.784
1954 0.735
1955 0.86
1956 1.07
1957 1.279
1958 1.421
1959 1.469
1960 1.439
1961 1.403
1962 1.456
1963 1.66
1964 1.985
1965 2.411
1966 2.811
1967 2.813
1968 2.134
1969 0.849
1970 -0.751
1971 -2.326
1972 -3.545
1973 -4.123
1974 -3.936
1975 -3.305
1976 -2.581
1977 -1.552
1978 0.081
1979 2.169
1980 4.448
1981 6.473
1982 7.612
1983 7.565
1984 6.606
1985 5.318
1986 4.178
1987 3.38
1988 2.98
1989 2.958
1990 3.1
1991 3.21
1992 3.292
1993 3.396
1994 3.514
1995 3.647
1996 3.791
1997 3.915
1998 3.995
1999 4.037
2000 4.054
2001 4.069
2002 4.113
2003 4.201
2004 4.321
2005 4.446
2006 4.542
2007 4.592
2008 4.593
2009 4.548
2010 4.478
2011 4.4
2012 4.307
2013 4.192
2014 4.059
2015 3.918
2016 3.78
2017 3.646
2018 3.518
2019 3.398
2020 3.281
2021 3.169
2022 3.066
2023 2.979
2024 2.906
2025 2.842
2026 2.782
2027 2.719
2028 2.649
2029 2.573
2030 2.496
2031 2.424
2032 2.363
2033 2.318
2034 2.287
2035 2.264
2036 2.241
2037 2.214
2038 2.182
2039 2.143
2040 2.103
2041 2.064
2042 2.026
2043 1.988
2044 1.95
2045 1.913
2046 1.875
2047 1.839
2048 1.807
2049 1.776
2050 1.747
2051 1.718
2052 1.689
2053 1.658
2054 1.626
2055 1.594
2056 1.562
2057 1.53
2058 1.497
2059 1.464
2060 1.431
2061 1.398
2062 1.366
2063 1.334
2064 1.302
2065 1.27
2066 1.239
2067 1.208
2068 1.177
2069 1.146
2070 1.115
2071 1.085
2072 1.055
2073 1.026
2074 0.998
2075 0.971
2076 0.944
2077 0.918
2078 0.892
2079 0.867
2080 0.843
2081 0.819
2082 0.795
2083 0.773
2084 0.751
2085 0.73
2086 0.709
2087 0.689
2088 0.669
2089 0.649
2090 0.63
2091 0.611
2092 0.592
2093 0.574
2094 0.556
2095 0.538
2096 0.52
2097 0.502
2098 0.485
2099 0.467