Year Percent
1950 2.637
1951 2.754
1952 2.935
1953 3.019
1954 3.034
1955 3.008
1956 2.963
1957 2.917
1958 2.883
1959 2.864
1960 2.85
1961 2.819
1962 2.748
1963 2.619
1964 2.439
1965 2.238
1966 2.048
1967 1.886
1968 1.763
1969 1.68
1970 1.613
1971 1.546
1972 1.5
1973 1.5
1974 1.539
1975 1.601
1976 1.659
1977 1.675
1978 1.615
1979 1.482
1980 1.32
1981 1.169
1982 1.04
1983 0.932
1984 0.85
1985 0.777
1986 0.705
1987 0.679
1988 0.743
1989 0.889
1990 1.081
1991 1.267
1992 1.392
1993 1.419
1994 1.351
1995 1.233
1996 1.116
1997 1.011
1998 0.92
1999 0.845
2000 0.774
2001 0.698
2002 0.627
2003 0.574
2004 0.535
2005 0.508
2006 0.485
2007 0.454
2008 0.408
2009 0.348
2010 0.281
2011 0.217
2012 0.17
2013 0.153
2014 0.166
2015 0.195
2016 0.225
2017 0.244
2018 0.246
2019 0.228
2020 0.2
2021 0.173
2022 0.15
2023 0.131
2024 0.115
2025 0.102
2026 0.087
2027 0.069
2028 0.049
2029 0.026
2030 0.001
2031 -0.025
2032 -0.051
2033 -0.079
2034 -0.108
2035 -0.138
2036 -0.168
2037 -0.198
2038 -0.227
2039 -0.255
2040 -0.282
2041 -0.309
2042 -0.333
2043 -0.356
2044 -0.377
2045 -0.395
2046 -0.412
2047 -0.427
2048 -0.439
2049 -0.447
2050 -0.453
2051 -0.457
2052 -0.46
2053 -0.463
2054 -0.465
2055 -0.465
2056 -0.466
2057 -0.466
2058 -0.467
2059 -0.469
2060 -0.472
2061 -0.474
2062 -0.477
2063 -0.481
2064 -0.486
2065 -0.492
2066 -0.499
2067 -0.506
2068 -0.513
2069 -0.523
2070 -0.532
2071 -0.541
2072 -0.551
2073 -0.56
2074 -0.569
2075 -0.578
2076 -0.586
2077 -0.594
2078 -0.601
2079 -0.606
2080 -0.61
2081 -0.613
2082 -0.616
2083 -0.617
2084 -0.618
2085 -0.618
2086 -0.616
2087 -0.614
2088 -0.611
2089 -0.606
2090 -0.601
2091 -0.595
2092 -0.588
2093 -0.579
2094 -0.57
2095 -0.56
2096 -0.549
2097 -0.537
2098 -0.524
2099 -0.509