Year	Percent
1991	53.441
1992	44.932
1993	37.766
1994	29.735
1995	60.166
1996	58.018
1997	57.195
1998	57.37
1999	57.429
2000	58.944
2001	53.906
2002	58.494
2003	49.642
2004	41.198
2005	33.191
2006	26.987
2007	26.314
2008	21.896
2009	19.58
2010	21.394
2011	12.049
2012	14.18
2013	16.542
2014	17.975
2015	19.823
2016	22.077
2017	21.793
2018	22.047
2019	21.719
2020	21.07
2021	20.015
2022	19.707