Year	Number
1976	2.561424987464306
1977	2.5938707673730153
1978	3.300774266716924
1979	3.68189747122402
1980	3.708593499278879
1981	2.388741679673012
1982	2.773027391955266
1983	2.6425557212287005
1984	2.4007209447927984
1985	2.206446249043289
1986	2.824029678637402
1987	3.56442901244333
1988	3.7626881286905425
1989	3.1032987195808
1990	2.624275293934308
1991	3.442243320916195
1992	2.9758897895567973
1993	5.0990220884963975
1994	8.345595472052455
1995	6.981004625713892
1996	7.7800346892672705
1997	5.760264569088597
1999	5.964245069439851
2000	3.8589124591406865
2001	1.6678917389220138
2002	2.5350469899944796
2003	1.2240699633836307
2004	0.46196039556584956
2005	0.3532755932103768
2006	0.3619663757221778
2007	0.36454428863956123
2008	0.29176501459558657
2009	0.6381229572163789
2010	0.7925746258785371
2011	0.7922224364624021
2012	1.1351853478023166
2013	0.778697041386536
2014	0.8179465958027778
2015	1.0038233657005187
2016	1.1779352746176308
2017	1.1714650635467259
2018	0.9573339848861419
2019	1.1107220950188448
2020	1.8059496623798696
2021	1.5615357940513057
2022	1.057950322749488
2023	1.2208264500930712