Year	Percent
1991	51.323
1992	49.614
1993	51.477
1994	45.353
1995	55.046
1996	66.618
1997	65.961
1998	56.894
1999	57.111
2000	60.323
2001	59.409
2002	53.989
2003	53.241
2004	51.072
2005	49.47
2006	47.975
2007	46.6
2008	43.924
2009	36.938
2010	35.068
2011	35.996
2012	35.405
2013	41.468
2014	40.956
2015	37.508
2016	34.805
2017	34.692
2018	34.772
2019	35.327
2020	35.152
2021	34.907
2022	35.211