Year	Number
1975	2.4330775193793097
1976	2.656445962012064
1977	2.534817777173279
1978	2.335114420877019
1979	2.6293739108921033
1980	3.138375543489921
1981	4.082433152210159
1982	4.373757172972064
1983	4.636642641269633
1984	3.914878066768836
1985	5.155429903065974
1986	5.866023968322712
1987	4.019355053342552
1988	4.429786470887197
1989	3.2377522781328434
1990	1.672575882002307
1991	2.430091650613047
1992	2.4517564219570422
1993	2.4460441954467265
1994	1.9702289955112349
1995	1.9418224108548363
1996	1.9417985296210583
1997	1.7943244354685823
1998	1.5173085952987064
1999	1.773551991664327
2000	1.6487827064470888
2001	2.3236428739269153
2002	2.7244220708108533
2003	2.773728843891858
2004	2.132462049627905
2005	1.5668444552804464
2006	1.7748690505520648
2007	2.2364527977664883
2008	2.0014415856641046
2009	3.1164797193524016
2010	3.7549233090256537
2011	2.3412021723076646
2012	2.2724835464105495
2013	2.0991811605519164
2014	2.4656607982218817
2015	1.619711160056053
2016	1.246395831505878
2017	1.2110141593767363
2018	0.8880342663263366
2019	1.5458484900259013
2020	1.0547970704671972
2021	1.8100330350886533
2022	1.4626760101006975
2023	1.5380574300225076