Annual years
1960 42.85411092770643
1961 43.36649687296321
1962 43.954763473139025
1963 44.27146748326769
1964 44.931809805846434
1965 45.11924658411779
1966 45.60364732337895
1967 46.033639091292386
1968 46.55012988193936
1969 46.901187313605526
1970 46.4146636159612
1971 44.12184393530119
1972 47.87693963934154
1973 48.407028411839875
1974 48.51528682606687
1975 48.70091663897487
1976 49.277955178212416
1977 49.85860072215302
1978 50.22902555633006
1979 50.657288013690746
1980 51.16313327085992
1981 51.542985599446325
1982 51.76971429525569
1983 51.56515401299903
1984 51.70436056188602
1985 51.948304486562414
1986 52.36853937787926
1987 52.72615839119904
1988 52.68860031356102
1989 53.325337983209344
1990 53.55564679079413
1991 53.322289109238326
1992 53.64322072552884
1993 53.888748218787654
1994 54.234642399318496
1995 54.42999144647849
1996 54.565797804637704
1997 55.00914742548013
1998 55.24799411024841
1999 56.187800595524536
2000 56.63170080245032
2001 57.01124339586935
2002 57.4175623707504
2003 57.85886586840762
2004 58.179602996072205
2005 58.60053948424088
2006 59.23873613693904
2007 59.5910104996775
2008 59.773684274088815
2009 60.451432222413345
2010 60.89852696243462
2011 61.455360850920115
2012 61.77098085570556
2013 62.10515024469133
2014 62.4180887324393
2015 62.75171706141373
2016 63.16565331525459
2017 63.54116945810773
2018 63.88110119695857
2019 64.21240643971596
2020 63.748248344655764
2021 63.40066424565102
2022 64.04892352081865