Year	Number
1960	6.437209302325582
1961	10.373333333333333
1962	14.572727272727272
1963	13.038461538461538
1964	16.304761904761904
1965	24.458285714285715
1966	14.668909090909091
1967	18.81178947368421
1968	16.06344
1969	12.824342857142858
1970	11.563488372093023
1971	5.583376874595107
1972	4.267762365114611
1973	5.734739442027315
1974	5.841327355277781
1975	11.620108385749118
1976	7.212919364283001
1977	6.999457079718904
1978	7.011296341264186
1979	4.909708053752387
1980	14.505927344412791
1981	13.975687427647305
1982	36.35495171776242
1983	29.78933592014441
1984	28.899772073680758
1985	49.141724975224335
1986	28.691388091510216
1987	28.83362268926729
1988	32.547081834984255
1989	45.982031350389086
1990	91.93195307455045
1991	24.212366396514906
1992	22.375932611916554
1993	18.177434125730755
1994	13.50326819204437
1995	5.115976420010774
1996	4.159756606965883
1997	5.197309244629633
1998	4.376400059100876
1999	5.48161231885735
2000	8.118534987442821
2001	9.929484653610192
2002	18.557191993321524
2003	22.654644676481325
2004	8.059506974647054
2005	8.342801444717718
2006	4.78734909996233
2007	3.737502635006958
2008	3.4012018367119166
2009	2.346230260512078
2010	1.686867526320952
2011	1.8134776284362961
2012	1.638299796819908
2013	1.5367429024335955
2014	1.99436792553134
2015	2.3380672274965275
2016	2.0470854677172348
2017	1.8359043968534672
2018	2.2360745215404805
2019	1.9088621430307808
2020	1.5231297718558237
2021	2.4080919161428627
2022	2.771509170709346