Year	Percent
1991	64.31
1992	65.427
1993	65.537
1994	64.576
1995	62.624
1996	59.737
1997	60.875
1998	62.489
1999	57.771
2000	58.959
2001	57.743
2002	55.57
2003	56.67
2004	54.915
2005	54.164
2006	55.271
2007	58.317
2008	53.405
2009	47.724
2010	45.866
2011	47.196
2012	45.048
2013	43.995
2014	44.423
2015	43.3
2016	41.969
2017	42.531
2018	42.637
2019	42.658
2020	42.544
2021	42.319
2022	41.967