Year	Number
1996	0.421715974807739
1998	0.381433337926865
2000	0.396205484867096
2002	0.392881572246552
2003	0.330509543418884
2004	0.316001296043396
2005	0.311466783285141
2006	0.27938786149025
2007	0.267617672681808
2008	0.271060198545456
2009	0.272184789180756
2010	0.267576217651367
2011	0.260717630386353
2012	0.226807355880737
2013	0.231508240103722
2014	0.20011305809021
2015	0.204930633306503
2016	0.214360997080803
2017	0.222477972507477
2018	0.2210383862257
2019	0.234910249710083
2020	0.237614139914513
2021	0.234690770506859
2022	0.233039766550064