Year	Percent
1991	14.849
1992	14.993
1993	14.498
1994	15.852
1995	13.821
1996	12.515
1997	12.707
1998	10.868
1999	11.208
2000	9.77
2001	10.648
2002	9.806
2003	8.316
2004	6.366
2005	6.135
2006	6.096
2007	5.162
2008	5.24
2009	5.293
2010	5.064
2011	5.247
2012	5.129
2013	5.119
2014	5.168
2015	5.049
2016	5.208
2017	5.124
2018	4.99
2019	4.881
2020	4.847
2021	4.814
2022	4.776