Annual years
1960 42.7231428623187
1961 43.195550285380165
1962 43.69148351398484
1963 43.846102463578276
1964 44.534336158763196
1965 44.55655299474613
1966 44.94214210945094
1967 45.51678944831293
1968 45.88256536874679
1969 46.138980968356044
1970 45.04983731145693
1971 42.292114215821805
1972 46.69505895703211
1973 47.255800304258806
1974 47.26268210835678
1975 47.306924438522536
1976 47.915195883400884
1977 48.58224602589514
1978 48.95038549774191
1979 49.41182161033092
1980 49.908030388165045
1981 50.200001295735056
1982 50.41478228792704
1983 49.94332067188398
1984 50.04692068786822
1985 50.397256963205535
1986 51.02299449517685
1987 51.588752923955745
1988 51.467387172958524
1989 52.35084302283997
1990 52.65378730861273
1991 52.37482821318062
1992 52.94832062994237
1993 53.413255217203925
1994 53.998811850833675
1995 54.41116179762028
1996 54.543363671766286
1997 55.17993948505876
1998 55.41284617862207
1999 56.608641036422945
2000 57.066160858641986
2001 57.515275925664085
2002 57.95028267622472
2003 58.453630548084476
2004 58.77345726241524
2005 59.387415914187734
2006 59.942639801517544
2007 60.34717017576683
2008 60.476374771829256
2009 61.327997604479144
2010 61.82756744921935
2011 62.47208474573782
2012 62.848514616804124
2013 63.19409575872412
2014 63.577512752047355
2015 63.95788920578941
2016 64.47164293263903
2017 64.87272864871503
2018 65.27719305985798
2019 65.64179339728979
2020 65.10590483040735
2021 64.74778514269326
2022 65.41607448651483