Year	Number
1976	2.393286292249229
1977	2.1240744127480693
1978	2.41251918012638
1979	2.4648724961633164
1980	2.039789708413827
1981	1.6521052028447214
1982	1.986696974306909
1983	1.955153782163654
1984	1.422852413574241
1985	0.9775966401309888
1986	1.2098176081300924
1987	1.8756476805889257
1988	2.460876187920271
1989	2.315753472241433
1990	1.5779305399637054
1991	1.6378361559899555
1992	1.4063913766239708
1993	1.4439692322366253
1994	2.2283256848845947
1995	2.1012017657073736
1996	2.4839979206626546
1997	2.5418866288447566
1998	2.2903063113138895
1999	2.743118972634037
2000	2.180463742394369
2001	2.1590541168403035
2002	2.4849164800104004
2003	2.799253726560989
2004	3.1012880103329676
2005	3.3088701143279797
2006	4.527352971439269
2007	4.1794299582515215
2008	3.710167663198542
2009	5.812437928729155
2010	4.4057809253696565
2011	3.308811151596347
2012	3.6743726213728647
2013	3.1631892038002416
2014	3.1153041407735236
2015	3.8127077780744596
2016	3.2232200450499224
2017	3.0553864774488484
2018	3.366377459481612
2019	4.970593679577196
2020	7.241749574476029
2021	5.304047476037859
2022	3.990453538425079