Year Percent
1950 2.024
1951 2.279
1952 2.706
1953 2.974
1954 3.106
1955 3.121
1956 3.041
1957 2.883
1958 2.665
1959 2.403
1960 2.117
1961 1.825
1962 1.548
1963 1.304
1964 1.1
1965 0.912
1966 0.734
1967 0.625
1968 0.641
1969 0.774
1970 0.978
1971 1.188
1972 1.353
1973 1.44
1974 1.449
1975 1.414
1976 1.378
1977 1.368
1978 1.396
1979 1.458
1980 1.536
1981 1.601
1982 1.612
1983 1.541
1984 1.397
1985 1.212
1986 1.028
1987 0.872
1988 0.763
1989 0.701
1990 0.666
1991 0.634
1992 0.586
1993 0.516
1994 0.424
1995 0.321
1996 0.226
1997 0.166
1998 0.162
1999 0.215
2000 0.3
2001 0.387
2002 0.457
2003 0.494
2004 0.499
2005 0.486
2006 0.473
2007 0.467
2008 0.47
2009 0.481
2010 0.496
2011 0.505
2012 0.502
2013 0.479
2014 0.437
2015 0.385
2016 0.331
2017 0.279
2018 0.23
2019 0.187
2020 0.144
2021 0.101
2022 0.06
2023 0.023
2024 -0.01
2025 -0.04
2026 -0.069
2027 -0.095
2028 -0.118
2029 -0.137
2030 -0.154
2031 -0.17
2032 -0.184
2033 -0.198
2034 -0.211
2035 -0.224
2036 -0.235
2037 -0.247
2038 -0.26
2039 -0.272
2040 -0.285
2041 -0.298
2042 -0.312
2043 -0.328
2044 -0.346
2045 -0.365
2046 -0.384
2047 -0.403
2048 -0.422
2049 -0.441
2050 -0.46
2051 -0.478
2052 -0.496
2053 -0.513
2054 -0.529
2055 -0.543
2056 -0.557
2057 -0.57
2058 -0.581
2059 -0.59
2060 -0.598
2061 -0.604
2062 -0.61
2063 -0.613
2064 -0.615
2065 -0.615
2066 -0.614
2067 -0.613
2068 -0.61
2069 -0.608
2070 -0.605
2071 -0.602
2072 -0.598
2073 -0.592
2074 -0.586
2075 -0.579
2076 -0.573
2077 -0.566
2078 -0.56
2079 -0.554
2080 -0.549
2081 -0.543
2082 -0.538
2083 -0.534
2084 -0.53
2085 -0.526
2086 -0.522
2087 -0.52
2088 -0.517
2089 -0.514
2090 -0.513
2091 -0.511
2092 -0.51
2093 -0.507
2094 -0.505
2095 -0.503
2096 -0.501
2097 -0.498
2098 -0.495
2099 -0.492