Year	Number
1978	1.070416702606251
1979	1.2361149919777958
1980	1.5879235858061573
1981	1.7112934953551926
1982	1.0974682903524822
1983	0.8755217317485318
1984	1.128026895847359
1985	1.2502998301259116
1986	1.3985651511151673
1987	1.3173685631586525
1988	1.552233910799997
1989	2.126481465947632
1990	3.1481098638692684
1991	7.483962698820917
1992	3.139890398567088
1993	3.904836313932988
1994	5.452301486438772
1995	6.301529276316974
1996	3.387454905464822
1997	3.1089425653381517
1998	1.8235540758890865
1999	1.861540807609141
2000	2.840485463990526
2001	4.364452796030323
2002	3.5108378402258844
2003	1.9737062952130093
2004	1.0804285573048964
2005	1.3207952778239218
2006	1.5054857389914376
2007	1.5732497858975443
2008	2.2770426701592816
2009	1.556843171183924
2010	0.967717867527132
2011	0.8284672244029704
2012	0.8348775375124293
2013	0.9059566459006217
2014	0.9937485826405592
2015	1.0165340522048234
2016	1.1608111866657824
2017	1.0836011122211975
2018	1.0683179631923627
2019	1.0877686399629705
2020	0.998038198246162
2021	0.9904189889134299
2022	1.0775875300111153