Year	Number
1995	3.0651920562440242
1996	2.941750111446127
1997	3.0424161397059164
1998	3.289720087832217
1999	3.136673151817247
2000	4.069758439957849
2001	4.635968047450274
2002	4.512547088943619
2003	3.9163198153509224
2004	4.468527616832059
2005	4.51866671500085
2006	3.9287059061865928
2007	3.3162379484613735
2008	3.8862144693948077
2009	6.807206607873799
2010	10.6805395335056
2011	9.990786801521066
2012	6.48696926251952
2013	7.738592350615871
2014	6.946589055166568
2015	9.415654226795883
2016	8.491222926353794
2017	7.080644318313875
2018	6.989619676743862
2019	5.512553442733668
2020	5.1390477809322315
2021	4.8973700507578695
2022	6.509652650974376