Year	Percent
1991	40.351
1992	38.005
1993	36.846
1994	38.451
1995	36.67
1996	36.533
1997	36.396
1998	34.508
1999	32.65
2000	30.591
2001	30.231
2002	33.985
2003	33.382
2004	35.341
2005	35.142
2006	35.216
2007	36.98
2008	37.934
2009	36.572
2010	34.972
2011	35.582
2012	34.779
2013	34.82
2014	35.465
2015	35.019
2016	36.724
2017	35.872
2018	35.26
2019	34.943
2020	34.65
2021	34.579
2022	34.516