Year	Percent
1991	51.38
1992	50.939
1993	51.452
1994	52.81
1995	52.755
1996	53.064
1997	53.592
1998	54.796
1999	54.486
2000	54.711
2001	53.132
2002	51.142
2003	49.34
2004	48.971
2005	49.519
2006	49.298
2007	48.742
2008	47.121
2009	43.835
2010	41.73
2011	41.494
2012	42.078
2013	42.761
2014	43.784
2015	44.945
2016	45.776
2017	46.057
2018	45.966
2019	45.595
2020	45.306
2021	44.949
2022	44.595