Year Percent
1950 1.534
1951 1.611
1952 1.751
1953 1.866
1954 1.962
1955 2.046
1956 2.125
1957 2.202
1958 2.282
1959 2.364
1960 2.445
1961 2.517
1962 2.572
1963 2.603
1964 2.613
1965 2.61
1966 2.606
1967 2.609
1968 2.622
1969 2.645
1970 2.672
1971 2.697
1972 2.718
1973 2.732
1974 2.743
1975 2.746
1976 2.744
1977 2.752
1978 2.781
1979 2.826
1980 2.856
1981 2.851
1982 2.843
1983 2.862
1984 2.892
1985 2.955
1986 3.016
1987 2.897
1988 2.459
1989 1.748
1990 0.896
1991 0.085
1992 -0.454
1993 -0.534
1994 -0.144
1995 0.499
1996 1.139
1997 1.701
1998 2.18
1999 2.548
2000 2.867
2001 3.167
2002 3.334
2003 3.266
2004 2.995
2005 2.625
2006 2.27
2007 2
2008 1.855
2009 1.835
2010 1.871
2011 1.901
2012 1.932
2013 1.989
2014 2.064
2015 2.151
2016 2.238
2017 2.301
2018 2.321
2019 2.3
2020 2.26
2021 2.22
2022 2.186
2023 2.158
2024 2.138
2025 2.119
2026 2.098
2027 2.077
2028 2.06
2029 2.045
2030 2.032
2031 2.017
2032 2.001
2033 1.983
2034 1.964
2035 1.942
2036 1.92
2037 1.896
2038 1.869
2039 1.84
2040 1.809
2041 1.778
2042 1.745
2043 1.711
2044 1.677
2045 1.641
2046 1.606
2047 1.571
2048 1.537
2049 1.505
2050 1.473
2051 1.442
2052 1.411
2053 1.382
2054 1.354
2055 1.327
2056 1.3
2057 1.274
2058 1.248
2059 1.223
2060 1.199
2061 1.175
2062 1.151
2063 1.127
2064 1.103
2065 1.08
2066 1.056
2067 1.032
2068 1.008
2069 0.983
2070 0.957
2071 0.932
2072 0.908
2073 0.883
2074 0.859
2075 0.836
2076 0.812
2077 0.789
2078 0.767
2079 0.745
2080 0.724
2081 0.703
2082 0.682
2083 0.662
2084 0.642
2085 0.622
2086 0.602
2087 0.583
2088 0.564
2089 0.546
2090 0.527
2091 0.509
2092 0.491
2093 0.474
2094 0.456
2095 0.439
2096 0.422
2097 0.405
2098 0.389
2099 0.372