Year	Number
1965	9.603051483314633
1966	11.905892033466293
1967	10.339589548624383
1968	11.79837800421181
1969	16.662622834246108
1970	16.022377766187073
1971	16.94359805947524
1972	15.502650843496308
1973	7.287454837610586
1974	5.891932162613388
1975	9.955388300472375
1976	10.716506463007482
1977	8.65097996118249
1978	7.520983497060218
1979	5.446735501833767
1980	5.80477390843634
1981	10.892970832679191
1982	12.110098417113294
1983	14.949823726606436
1984	18.75850176421226
1985	20.233293954424834
1986	19.50202843137006
1987	13.794587643233818
1988	13.6991374514022
1989	13.261584225122997
1990	10.225500096174876
1991	5.2904802217842954
1992	3.0450899743758235
1993	2.8848924312567377
1994	3.0474710674987087
1995	2.8034145002528845
1996	2.9068435871228626
1997	3.043212702500273
1998	3.471114237865978
1999	4.541104453250015
2000	5.558053526666586
2001	5.857168116091082
2002	5.313230795733707
2003	5.31527082304032
2004	4.9656572645692405
2005	3.982111441661236
2006	4.022763156756753
2007	3.8954465202793127
2008	4.192719997904161
2009	4.507216869430547
2010	4.775228863130931
2011	9.597070978489349
2012	12.41587896946382
2013	13.014205444310768
2014	15.445119573570137
2015	16.19655976727771
2016	13.798997519850328
2017	5.977210645933613
2018	4.880648317204905
2019	5.252190597619176
2020	7.876189575978506
2021	9.318555381847803
2022	13.999989144713433
2023	10.465880306460582