Year	Number
1971	1.5789513428433177
1972	2.517381328788262
1973	2.032427083649422
1974	1.7288328608450445
1975	0.9094985536960289
1976	1.5383438921536503
1977	1.509518359788953
1978	1.503983870607266
1979	2.2374556647458954
1980	0.6434703647148406
1981	0.6997056166326239
1982	0.30353946719423136
1983	0.36646471620137494
1984	0.40330375230839116
1985	0.25178384812956994
1986	0.5555135810282065
1987	0.5824962985109343
1988	0.47496007834885695
1989	0.4974619782515378
1990	0.22607532767003002
1991	0.902282899426191
1992	1.530856561133218
1993	1.5552117426558776
1994	2.831125182623905
1995	2.865964574972765
1996	3.380878530677561
1997	2.822270246367914
1998	3.011914528281513
1999	2.5088860502843136
2000	1.5894327330427387
2001	1.2838003919116494
2002	0.7802864327591782
2003	0.5246966442442935
2004	1.441563962367741
2005	1.3923637485869529
2006	2.0474180870862146
2007	2.9051600195042115
2008	2.9428341487235783
2009	4.644867832401199
2010	5.400496163434934
2011	5.20164137379831
2012	6.317237902557631
2013	6.579681206509961
2014	4.935470723152266
2015	5.053589177870199
2016	5.825415843927456
2017	5.737339039265783
2018	5.018408701758819
2019	5.8240894557662966
2020	7.402252390526954
2021	6.476038372778983
2022	5.196713385044083