Year	Percent
1991	53.698
1992	53.373
1993	53.786
1994	53.361
1995	53.525
1996	53.133
1997	52.741
1998	52.179
1999	51.597
2000	51.453
2001	51.043
2002	50.345
2003	50.082
2004	49.335
2005	49.163
2006	48.584
2007	47.914
2008	48.128
2009	48.472
2010	48.203
2011	47.454
2012	47.316
2013	47.069
2014	46.776
2015	46.928
2016	46.791
2017	46.734
2018	46.646
2019	46.557
2020	46.469
2021	46.382
2022	46.298