Annual years
1960 41.42254577644811
1961 41.73973935807562
1962 42.20072057552484
1963 42.440620261288736
1964 42.89083772694231
1965 43.029451291311915
1966 42.984090052141084
1967 43.23217833178633
1968 43.67073477598762
1969 43.91130716747808
1970 44.369830237344054
1971 44.87080396884153
1972 44.98734365716508
1973 45.708795356985526
1974 45.920461663804296
1975 46.306432704087854
1976 46.984952204866225
1977 47.447803211481514
1978 47.74858696016245
1979 48.210028914599825
1980 48.57245575503308
1981 48.93781946044994
1982 49.176041684886975
1983 48.33214819239349
1984 48.36180774515386
1985 48.61274752680017
1986 49.00706987375912
1987 49.338121581985504
1988 49.02019767545751
1989 49.88486949339315
1990 49.824307633487955
1991 49.69963102760735
1992 49.472160671427496
1993 49.69693251878119
1994 50.0021598833425
1995 50.11417407159537
1996 50.0485283330994
1997 50.21533670966416
1998 49.927786874302484
1999 50.64083818417793
2000 51.26454480280286
2001 51.53632182500615
2002 51.89134243641399
2003 52.36952152080998
2004 52.84880711910819
2005 53.462195048548054
2006 54.213301069582855
2007 54.84902854487477
2008 55.45071260524644
2009 56.219613071159316
2010 56.84736568908038
2011 57.55861068509845
2012 58.14101324867884
2013 58.668043004745975
2014 59.142658201912674
2015 59.562981700058565
2016 60.069024673119515
2017 60.477138457149515
2018 60.863027538892126
2019 61.244290518923414
2020 60.848894424466415
2021 60.24174346318638
2022 60.76439997752779