Year	% of cohort
1997	42.2123794555664
1998	44.9397392272949
2000	56.1137619018555
2001	65.0130920410156
2002	54.2571105957031
2003	52.4589500427246
2004	55.6271095275879
2005	53.5882987976074
2006	53.3292007446289
2007	51.9559707641602
2010	60.7437896728516
2011	63.6279106140137
2015	68.7873611450195
2016	73.8733291625977
2017	79.1833572387695
2018	76.1522521972656
2019	75.2577209472656