Year	Percent
1991	48.025
1992	47.578
1993	47.493
1994	47.525
1995	47.443
1996	46.833
1997	50.012
1998	49.634
1999	49.534
2000	49.227
2001	48.886
2002	48.753
2003	48.081
2004	47.724
2005	47.461
2006	46.924
2007	46.377
2008	45.599
2009	44.625
2010	43.554
2011	44.209
2012	44.492
2013	44.497
2014	44.151
2015	44.164
2016	45.147
2017	45.216
2018	45.161
2019	45.106
2020	45.052
2021	44.994
2022	44.938