Year Percent
1950 15.425
1951 12.2
1952 7.673
1953 6.068
1954 6.079
1955 6.947
1956 8.036
1957 8.895
1958 9.302
1959 9.242
1960 8.878
1961 8.522
1962 8.458
1963 8.788
1964 9.313
1965 10.051
1966 10.694
1967 10.226
1968 8.175
1969 5.059
1970 1.35
1971 -2.254
1972 -4.068
1973 -2.278
1974 3.131
1975 9.919
1976 15.004
1977 16.599
1978 15.041
1979 11.729
1980 8.2
1981 5.392
1982 3.547
1983 2.669
1984 2.68
1985 3.099
1986 3.446
1987 3.609
1988 3.612
1989 3.462
1990 3.293
1991 3.224
1992 3.224
1993 3.243
1994 3.295
1995 3.296
1996 3.257
1997 3.469
1998 4.16
1999 5.201
2000 6.348
2001 7.263
2002 7.504
2003 6.879
2004 5.599
2005 4.093
2006 2.745
2007 1.768
2008 1.264
2009 1.227
2010 1.415
2011 1.588
2012 1.734
2013 1.902
2014 2.072
2015 2.256
2016 2.449
2017 2.592
2018 2.63
2019 2.569
2020 2.459
2021 2.35
2022 2.259
2023 2.187
2024 2.133
2025 2.087
2026 2.037
2027 1.982
2028 1.929
2029 1.878
2030 1.827
2031 1.778
2032 1.731
2033 1.686
2034 1.642
2035 1.6
2036 1.559
2037 1.52
2038 1.483
2039 1.448
2040 1.415
2041 1.382
2042 1.35
2043 1.32
2044 1.291
2045 1.264
2046 1.236
2047 1.207
2048 1.175
2049 1.142
2050 1.109
2051 1.075
2052 1.042
2053 1.009
2054 0.976
2055 0.944
2056 0.913
2057 0.882
2058 0.852
2059 0.825
2060 0.797
2061 0.77
2062 0.745
2063 0.72
2064 0.696
2065 0.672
2066 0.65
2067 0.628
2068 0.608
2069 0.589
2070 0.572
2071 0.555
2072 0.538
2073 0.522
2074 0.507
2075 0.492
2076 0.478
2077 0.464
2078 0.45
2079 0.437
2080 0.423
2081 0.41
2082 0.398
2083 0.386
2084 0.373
2085 0.361
2086 0.349
2087 0.337
2088 0.325
2089 0.312
2090 0.299
2091 0.286
2092 0.273
2093 0.26
2094 0.248
2095 0.235
2096 0.222
2097 0.209
2098 0.196
2099 0.183