Annual years
1960 41.422545776448096
1961 41.739739358075624
1962 42.20072057552484
1963 42.44062026128874
1964 42.890837726942316
1965 43.02945129131193
1966 42.98409005214109
1967 43.232178331786336
1968 43.67073477598761
1969 43.91130716747807
1970 44.369830237344054
1971 44.870803968841535
1972 44.987343657165084
1973 45.708795356985526
1974 45.920461663804296
1975 46.30643270408786
1976 46.984952204866225
1977 47.44780321148152
1978 47.74858696016245
1979 48.210028914599825
1980 48.57245575503308
1981 48.93781946044994
1982 49.176041684886975
1983 48.332148192393504
1984 48.361807745153854
1985 48.612747526800185
1986 49.007069873759136
1987 49.33812158198551
1988 49.0201976754575
1989 49.88486949339314
1990 49.824307633487955
1991 49.69963102760737
1992 49.472160671427496
1993 49.69693251878119
1994 50.00215988334251
1995 50.11417407159537
1996 50.04852833309941
1997 50.21533670966416
1998 49.92778687430248
1999 50.64083818417793
2000 51.26454480280285
2001 51.53632182500615
2002 51.89134243641399
2003 52.36952152080999
2004 52.84880711910819
2005 53.462195048548054
2006 54.21330106958285
2007 54.84902854487474
2008 55.45071260524642
2009 56.2196130711593
2010 56.847365689080384
2011 57.55861068509845
2012 58.14101324867884
2013 58.668043004745975
2014 59.14265820191268
2015 59.56298170005856
2016 60.069024673119515
2017 60.47713845714953
2018 60.86302753889212
2019 61.24429051892341
2020 60.848894424466394
2021 60.24174346318637
2022 60.764399977527766