Annual years
1960 43.993486357175584
1961 44.274597971699215
1962 44.72700321049756
1963 44.95898203137488
1964 45.46666422028322
1965 45.578930199343404
1966 45.61956927750423
1967 45.69978400546966
1968 46.129198146610555
1969 46.2533660713396
1970 46.749806984342804
1971 47.376194394539155
1972 47.410074732442865
1973 48.022916589638044
1974 48.18447447386702
1975 48.35053525156468
1976 48.81282397826332
1977 49.30665371070862
1978 49.37630316139985
1979 49.637572973958214
1980 49.80575053531591
1981 49.905808946970026
1982 49.78598498401338
1983 49.26043192155872
1984 49.009751268056036
1985 49.24260011787955
1986 49.84187389028516
1987 50.221502781604606
1988 49.7846322220983
1989 50.91501429063781
1990 50.91116173177179
1991 51.03457423372003
1992 51.040660017270945
1993 51.43377713332655
1994 52.165338854236325
1995 51.815945406943115
1996 51.89583540938624
1997 52.20749324250528
1998 51.91186202261232
1999 52.652252769590405
2000 53.47936261453365
2001 53.74635483632314
2002 54.154940844522244
2003 54.391849081524434
2004 54.6448705416865
2005 55.010821683735294
2006 55.51032887037098
2007 55.973876771752884
2008 56.14065186934741
2009 57.10888011920211
2010 57.427193397876025
2011 58.04399700940767
2012 58.199426047075534
2013 58.43947798454929
2014 58.65528667477789
2015 58.95171518584268
2016 59.17742008525795
2017 59.52656542504803
2018 59.8236347881128
2019 60.142066000069924
2020 59.587721179492235
2021 59.03943971154157
2022 59.58385589822264