Year	Percent
1991	42.442
1992	42.765
1993	40.513
1994	40.351
1995	36.415
1996	38.29
1997	39.658
1998	41.852
1999	41.317
2000	40.902
2001	40.497
2002	39.262
2003	40.557
2004	42.142
2005	42.703
2006	43.733
2007	43.636
2008	43.426
2009	44.004
2010	42.1
2011	44.007
2012	43.928
2013	43.725
2014	43.196
2015	43.546
2016	42.897
2017	42.824
2018	42.916
2019	42.932
2020	42.58
2021	42.275
2022	42.008