Year	Number
1963	9.577282901788498
1964	2.4659869686252036
1965	2.232434788499863
1966	3.6185214030285304
1967	5.336788752093236
1968	6.878649439093301
1969	24.738911730958662
1970	22.112690059947862
1971	147.59845498021
1972	22.93884014901701
1973	26.066426922122815
1974	31.95902779495375
1975	16.435695823460836
1976	4.25571580120577
1977	3.177938509987188
1978	3.843919526618206
1979	2.5549191637608466
1980	2.8102362049862952
1981	2.2619909758349186
1982	2.5640408234484116
1983	2.4911604966704353
1984	2.129661553150926
1985	2.400489648062926
1986	2.4324134371547874
1987	1.9829632470960314
1988	1.6941309427227944
1989	1.7103137739980387
1990	1.848110789214239
1991	1.963580023185726
1992	2.082813352119769
1993	1.9605711072295522
1994	0.9690815272659914
1995	1.0121883917161014
1996	1.042718886222163
1997	1.0963679196438227
1998	1.1103965532847653
1999	1.2612785293507809
2000	1.1456893431064636
2001	1.2183389046629178
2002	1.1707118975035813
2003	1.1991011262698186
2004	1.3339082423687392
2005	1.6681104552611579
2006	1.7578761041989286
2007	2.591135952041778
2008	2.3012390561047003
2009	1.5219544878099183
2010	1.9526557962921538
2011	2.7356485574039326
2012	2.509225326597609
2013	2.2336541100553307
2014	1.910031458696551
2015	2.0395739865399163
2016	1.9184953817200303
2017	1.4278142455995941
2018	1.706636997113664
2019	1.8199659778562864
2020	1.6725518594535587
2021	1.7779165432517872
2022	2.0935895385914827