Year	Percent
1991	47.604
1992	48.298
1993	47.324
1994	46.894
1995	46.57
1996	46.191
1997	46.057
1998	46.052
1999	45.919
2000	45.539
2001	45.265
2002	45.096
2003	45.005
2004	43.924
2005	45.166
2006	45.111
2007	44.005
2008	43.496
2009	42.898
2010	42.408
2011	43.301
2012	43.969
2013	44.001
2014	44.385
2015	44.367
2016	43.08
2017	42.582
2018	42.53
2019	42.471
2020	42.409
2021	42.329
2022	42.25