1955 -9.44925 2.67619 1956 -7.28923 2.66425 1957 -8.08317 2.63744 1958 -3.39526 2.6175 1959 -5.92173 2.64454 1960 -3.95912 2.61917 1961 -1.39416 2.61437 1962 -0.0870268 2.60014 1963 -0.773136 2.58729 1964 -2.74849 2.57367 1965 -4.18455 2.54027 1966 -2.6908 2.52111 1967 -4.48019 2.49686 1968 -6.40262 2.4519 1969 -5.27305 2.45193 1970 -4.50278 2.43004 1971 -3.29149 2.3777 1972 -1.3057 2.38903 1973 -0.754062 2.39703 1974 -2.02352 2.43152 1975 -0.159983 2.44983 1976 -1.07873 2.41501 1977 -0.284795 2.41468 1978 0.0588854 2.40538 1979 0.160631 2.36927 1980 3.44091 2.35037 1981 5.01585 2.36044 1982 3.68446 2.34683 1983 0.904675 2.33581 1984 1.97702 2.35343 1985 3.69054 2.3278 1986 3.5761 2.32221 1987 3.06844 2.28364 1988 5.25939 2.29465 1989 4.86403 2.30612 1990 5.73414 2.24723 1991 6.63006 2.25529 1992 6.52498 2.24418 1993 5.10674 2.23008 1994 6.28239 2.26294 1995 4.70638 2.23596 1996 7.62337 2.24131 1997 7.63452 2.23921 1998 7.38209 2.22968 1999 9.95743 2.23228 2000 9.30053 2.24846 2001 11.7034 2.25417 2002 15.5411 2.2465 2003 17.6638 2.17361 2004 16.2949 2.08003 2005 15.8265 2.00726 2006 16.6051 1.97644 2007 14.7276 1.94592 2008 16.6461 1.92735 2009 18.3746 1.90444 2010 17.7849 1.90343 2011 18.0406 1.90249 2012 18.6126 1.89815 2013 20.7849 1.94293 2014 21.5367 1.94449 2015 23.3048 1.93018 2016 22.0017 1.93006 2017 24.7296 1.93445 2018 25.292 1.94187 2019 27.4311 1.95814 2020 27.8722 1.97322 2021 29.2435 2.03696 2022 30.8461 2.06227 2023 32.2778 2.06427