Year	Percent
1991	47.441
1992	46.079
1993	45.428
1994	45.907
1995	45.974
1996	46.39
1997	46.735
1998	46.355
1999	46.448
2000	47.596
2001	48.361
2002	48.546
2003	48.18
2004	48.717
2005	49.457
2006	50.092
2007	50.729
2008	50.924
2009	50.359
2010	49.588
2011	50.92
2012	51.754
2013	52.453
2014	52.598
2015	52.748
2016	52.575
2017	52.527
2018	52.436
2019	52.195
2020	51.867
2021	51.398
2022	50.873