Year	Number
1996	0.47480720281601
1998	0.435220897197723
2000	0.453906059265137
2002	0.436297506093979
2003	0.349641561508179
2004	0.330648332834244
2005	0.332869827747345
2006	0.289696484804153
2007	0.273920655250549
2008	0.273937970399857
2009	0.261115193367004
2010	0.254323482513428
2011	0.254974603652954
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