Year	Percent
1991	23.662
1992	20.138
1993	19.116
1994	17.995
1995	16.978
1996	17.101
1997	14.316
1998	15.124
1999	13.575
2000	14.105
2001	12.036
2002	11.608
2003	10.948
2004	10.446
2005	10.124
2006	9.97
2007	9.895
2008	8.923
2009	8.945
2010	8.872
2011	8.649
2012	8.256
2013	8.36
2014	8.356
2015	7.876
2016	6.807
2017	6.545
2018	6.289
2019	6.036
2020	5.814
2021	5.599
2022	5.413