Annual years
1960 41.22851361544349
1961 41.65831777539938
1962 42.15808239446765
1963 42.281542495751125
1964 43.00827302676921
1965 42.97901127023983
1966 43.362287267135564
1967 43.96140462897886
1968 44.32376383975462
1969 44.56589027596332
1970 43.24340675606594
1971 40.05736476590682
1972 45.04682880465114
1973 45.62924988423573
1974 45.5668846352835
1975 45.48100041109522
1976 46.100214234500626
1977 46.81774116403479
1978 47.13669061226612
1979 47.62372484480079
1980 48.08729172920325
1981 48.41985177789208
1982 48.706634808747424
1983 47.97907693104825
1984 48.04759896141019
1985 48.41756030325482
1986 49.060653443834354
1987 49.626441242518176
1988 49.441232434131855
1989 50.44195338295231
1990 50.6966756701623
1991 50.41391966504867
1992 51.0674694155414
1993 51.613214740847674
1994 52.29266573095224
1995 52.79980457452746
1996 52.9478056074757
1997 53.654579359858836
1998 53.953939505290926
1999 55.197995509641814
2000 55.7872822922983
2001 56.26721446949184
2002 56.74169501157946
2003 57.324300167460194
2004 57.80399709525775
2005 58.340116794752916
2006 58.938554191481444
2007 59.36777915640925
2008 59.50704061800546
2009 60.49938879160165
2010 60.96005609948409
2011 61.680115018665205
2012 62.25488902627857
2013 62.698315149659024
2014 63.11790889194163
2015 63.49043258103684
2016 64.01452215461406
2017 64.40959625491018
2018 64.81379753488562
2019 65.15100498979167
2020 64.6297215434214
2021 64.21049048576914
2022 64.9225785824994