Year	Number
1961	3.3326705979126383
1962	4.5977150692409525
1963	5.508933008608901
1964	10.280506330054692
1965	8.44276815770134
1966	12.314301663392897
1967	9.115205268308177
1968	11.397445806190422
1969	11.856398697003547
1970	7.977729888463134
1971	3.9143656187315705
1972	3.28629229546228
1973	3.1969357331578143
1974	2.8641800861190196
1975	4.170978266419263
1976	4.699128237809999
1977	5.43195353603161
1978	5.263203570120671
1979	4.500656768112845
1980	5.098626032385146
1981	5.8865767114485505
1982	5.204698037725942
1983	5.711255336050754
1984	7.671339100831754
1985	12.900464876144651
1986	11.046252219110775
1987	7.470936108335733
1988	5.352668476898813
1989	5.257024172159066
1990	7.302907766147569
1991	7.395991095732134
1992	7.813538765369858
1993	7.1965283854186355
1994	4.686822663511524
1995	4.8849585486447795
1996	4.594398437781755
1997	4.5651632294723985
1998	4.988863895299743
1999	4.683801884880228
2000	5.746981729177861
2001	5.917574529255342
2002	5.351002778998952
2003	4.817018149818249
2004	4.0595093804802245
2005	3.8394824197199102
2006	2.752757392695053
2007	2.7895653302799466
2008	2.9216231603626652
2009	2.4078649022502936
2010	2.9361714389224067
2011	4.10303229478361
2012	3.5689842217325025
2013	4.209122692529805
2014	4.378359106597153
2015	3.961980245057046
2016	4.8148957630385985
2017	4.780871486453514
2018	5.079976923811989
2019	3.633999788288711
2020	3.376675410277261
2021	4.0963348419712275
2022	4.396943304975064
2023	4.194049280978845