Year	Number
1978	1.6298593166901334
1979	2.0117179326323593
1980	1.3421662017723304
1981	1.5821312272629768
1982	0.750289133121164
1983	0.8429451272367522
1984	1.724663677130045
1985	1.7941495124593716
1986	2.7413589981708193
1987	1.9883695520213736
1988	1.7223378078787759
1989	1.7283947146471792
1990	1.8928940055577568
1991	1.5841950675526835
1992	2.2918134399204177
1993	2.1727610106806456
1994	2.023535839078775
1995	1.8844461928631553
1996	1.8174570795856206
1997	1.5321387590954048
1998	1.7503257854920737
1999	1.9460453607766852
2000	2.7354934401787023
2001	2.898503783321814
2002	2.4700506412745007
2003	2.1140758008049962
2004	2.755583050242137
2005	2.406581047056236
2006	2.4733795267538907
2007	2.2909316064988716
2008	2.000873296007122
2009	2.3349372773602686
2010	2.9865204350968773
2011	2.5148760671037205
2012	2.869059535329113
2013	3.36434577059095
2014	3.8763002761138226
2015	4.497859941521749
2016	5.0892730214539
2017	4.948935702012203
2018	4.408468049420752
2019	5.300968060866695
2020	6.317531491479171
2021	8.347467770503554
2022	6.957854248576227
2023	5.781802231143583