Year	Percent
1991	48.98
1992	50.131
1993	49.661
1994	49.228
1995	49.758
1996	48.932
1997	47.781
1998	48.942
1999	49.507
2000	48.491
2001	48.1
2002	48.762
2003	48.3
2004	46.465
2005	46.616
2006	46.365
2007	13.191
2008	12.731
2009	36.232
2010	36.465
2011	37.545
2012	36.816
2013	36.536
2014	36.956
2015	37.07
2016	37.863
2017	37.932
2018	37.925
2019	37.918
2020	37.911
2021	37.904
2022	37.897