Year	Number
1982	6.898465976414493
1983	7.689395595706828
1984	6.661202751738194
1985	4.09644009532334
1986	4.570698960591721
1987	5.51112463888503
1988	4.507456657546253
1989	4.2822778852363586
1990	6.028876803131316
1991	7.0767183170054935
1992	4.168198456918672
1993	4.495220336718976
1994	5.015126968675795
1995	5.052766792769959
1996	5.94702883552406
1997	11.075002320653919
1998	11.376853145807523
1999	10.300542859897778
2000	8.405593685034793
2001	9.98052930150962
2002	12.263266866834861
2003	9.855390348249077
2004	11.21646192713405
2005	12.43770367676933
2006	13.591927876678385
2007	16.067840305743058
2008	17.189329617639654
2009	23.0877806479521
2010	19.903789551002387
2011	17.505368322538793
2012	17.377527224982586
2013	18.00356519479806
2014	17.49224607420508
2015	16.54369640923833
2016	15.335414623835385
2017	14.12127565815297
2018	12.036615288394325
2019	12.580039212197978
2020	13.731598805076292
2021	10.80464389734489
2022	10.193271398845004
2023	11.196214702192085