Year	Number
1996	0.49002593755722
1998	0.463879197835922
2000	0.444508165121078
2002	0.319152474403381
2003	0.305009186267853
2004	0.321823000907898
2005	0.326336085796356
2006	0.280175864696503
2007	0.275495171546936
2008	0.277796775102615
2009	0.261115193367004
2010	0.254323482513428
2011	0.283599376678467
2012	0.236767888069153
2013	0.242341712117195
2014	0.207291051745415
2015	0.213819772005081
2016	0.219450056552887
2017	0.228199601173401
2018	0.225225403904915
2019	0.243729904294014
2020	0.247393816709518
2021	0.24306446313858
2022	0.240944445133209