Annual years
1960 41.42254577644811
1961 41.73973935807562
1962 42.20072057552484
1963 42.440620261288736
1964 42.890837726942316
1965 43.02945129131192
1966 42.98409005214109
1967 43.23217833178633
1968 43.67073477598762
1969 43.91130716747807
1970 44.369830237344054
1971 44.87080396884152
1972 44.98734365716508
1973 45.708795356985526
1974 45.9204616638043
1975 46.30643270408786
1976 46.984952204866225
1977 47.447803211481514
1978 47.748586960162456
1979 48.210028914599825
1980 48.56903418099322
1981 48.93441927578173
1982 49.172894287908285
1983 48.328804574878326
1984 48.35866359939197
1985 48.60968158598791
1986 49.00427579865428
1987 49.33539730731276
1988 49.01742856729974
1989 49.882379792870196
1990 49.82184751909303
1991 49.69684178106943
1992 49.469336733924436
1993 49.69437855183005
1994 49.999480437919495
1995 50.111315440101414
1996 50.0458116077966
1997 50.21272239814784
1998 49.925086744592576
1999 50.638129068404666
2000 51.2619441016462
2001 51.533762631328365
2002 51.88907114846192
2003 52.367395929974094
2004 52.84661812154037
2005 53.46017793170976
2006 54.21136823960079
2007 54.847107811125895
2008 55.44886260821744
2009 56.21789288382959
2010 56.84569722907262
2011 57.557144064124756
2012 58.139480025035034
2013 58.66668186756227
2014 59.14134689295086
2015 59.56161718045812
2016 60.06772333147744
2017 60.475893074858405
2018 60.86196642952607
2019 61.24317607009691
2020 60.84749279160246
2021 60.24063783266549
2022 60.7631048177053