Year	Number
1976	7.4715772943418655
1977	6.361767624979154
1978	6.022143049990845
1979	5.963907350825781
1980	5.436570796100075
1981	5.253322943509405
1982	5.965878068129939
1983	5.611462393127522
1984	5.0184915812388535
1985	5.842917439203574
1986	6.857527763172851
1987	6.572932714111404
1988	5.48988253657322
1989	5.418692059299777
1990	5.9509366626873135
1991	5.302558001953468
1992	3.205903024729837
1993	4.58854543853274
1994	5.212490996826499
1995	2.9285417137893597
1996	3.6351249798866547
1997	3.361876755007462
1998	3.7171252735726616
1999	4.131949045355821
2000	3.583726826891396
2001	4.600109829045066
2002	5.753625155420684
2003	5.420954400331118
2004	5.161862687430063
2005	4.947476011084993
2006	5.854433952392704
2007	4.8009189948332915
2008	0.3652856869389659
2009	0.5176250252122708
2010	0.4214607515160253
2011	0.37793441280207835
2012	0.429691428148897
2013	0.3135392566448562
2014	0.2896267905040442
2015	0.21588929347754823
2016	0.33054323290165444
2017	0.24680397994285638
2018	0.2198116297330907
2019	0.246212360850171
2020	0.33140148583312695
2021	0.3156274083500786
2022	0.36906185394822544
2023	0.37047939854469336