Year Percent
1950 2.156
1951 2.209
1952 2.316
1953 2.42
1954 2.511
1955 2.579
1956 2.614
1957 2.607
1958 2.564
1959 2.488
1960 2.393
1961 2.303
1962 2.249
1963 2.25
1964 2.306
1965 2.389
1966 2.467
1967 2.546
1968 2.632
1969 2.719
1970 2.805
1971 2.888
1972 2.959
1973 3.008
1974 3.036
1975 3.065
1976 3.102
1977 3.121
1978 3.103
1979 3.059
1980 2.979
1981 2.887
1982 2.896
1983 3.089
1984 3.431
1985 3.839
1986 4.189
1987 4.317
1988 4.127
1989 3.667
1990 3.082
1991 2.527
1992 2.122
1993 1.934
1994 1.951
1995 2.079
1996 2.199
1997 2.204
1998 2.032
1999 1.699
2000 1.289
2001 0.908
2002 0.67
2003 0.649
2004 0.843
2005 1.149
2006 1.451
2007 1.684
2008 1.822
2009 1.861
2010 1.853
2011 1.849
2012 1.851
2013 1.846
2014 1.836
2015 1.82
2016 1.796
2017 1.766
2018 1.731
2019 1.693
2020 1.652
2021 1.61
2022 1.568
2023 1.529
2024 1.493
2025 1.458
2026 1.424
2027 1.393
2028 1.363
2029 1.337
2030 1.313
2031 1.289
2032 1.268
2033 1.247
2034 1.229
2035 1.212
2036 1.195
2037 1.177
2038 1.159
2039 1.14
2040 1.121
2041 1.101
2042 1.081
2043 1.058
2044 1.035
2045 1.011
2046 0.986
2047 0.961
2048 0.937
2049 0.911
2050 0.886
2051 0.861
2052 0.835
2053 0.808
2054 0.782
2055 0.756
2056 0.729
2057 0.703
2058 0.677
2059 0.652
2060 0.627
2061 0.602
2062 0.578
2063 0.554
2064 0.53
2065 0.507
2066 0.484
2067 0.462
2068 0.439
2069 0.417
2070 0.395
2071 0.374
2072 0.354
2073 0.333
2074 0.313
2075 0.293
2076 0.274
2077 0.255
2078 0.237
2079 0.219
2080 0.201
2081 0.184
2082 0.167
2083 0.151
2084 0.135
2085 0.12
2086 0.105
2087 0.091
2088 0.076
2089 0.062
2090 0.048
2091 0.034
2092 0.02
2093 0.007
2094 -0.006
2095 -0.019
2096 -0.032
2097 -0.044
2098 -0.057
2099 -0.07