Year	Percent
1991	45.076
1992	47.019
1993	46.884
1994	46.763
1995	46.639
1996	46.509
1997	46.572
1998	46.888
1999	47.261
2000	47.175
2001	46.907
2002	46.611
2003	46.491
2004	45.966
2005	45.116
2006	45.646
2007	45.644
2008	46.91
2009	47.669
2010	48.545
2011	48.573
2012	48.567
2013	48.412
2014	48.495
2015	46.719
2016	48.886
2017	48.75
2018	48.613
2019	48.481
2020	48.355
2021	48.229
2022	48.112