Year	Percent
1991	50.261
1992	49.374
1993	52.307
1994	51.715
1995	54.105
1996	53.313
1997	53.898
1998	56.926
1999	55.566
2000	54.333
2001	52.896
2002	51.237
2003	49.878
2004	50.912
2005	51.636
2006	54.193
2007	52.483
2008	54.479
2009	49.722
2010	49.221
2011	48.371
2012	45.601
2013	47.039
2014	50.363
2015	53.117
2016	53.427
2017	53.613
2018	54.053
2019	55.059
2020	55.322
2021	55.071
2022	54.525