Year	Percent
1991	12.489
1992	12.07
1993	12.247
1994	12.034
1995	11.605
1996	11.403
1997	11.183
1998	10.677
1999	10.383
2000	10.229
2001	9.509
2002	9.53
2003	9.536
2004	9.362
2005	9.31
2006	9.496
2007	9.325
2008	9.309
2009	8.897
2010	8.614
2011	8.533
2012	8.366
2013	8.311
2014	8.127
2015	7.674
2016	7.915
2017	7.716
2018	7.59
2019	7.485
2020	7.403
2021	7.296
2022	7.216