Year	Percent
1991	32.137
1992	24.178
1993	24.994
1994	25.866
1995	25.472
1996	26.282
1997	27.109
1998	26.981
1999	26.089
2000	24.72
2001	26.109
2002	25.619
2003	25.734
2004	23.886
2005	24.161
2006	23.197
2007	22.888
2008	22.637
2009	21.504
2010	20.431
2011	17.265
2012	17.681
2013	17.464
2014	14.88
2015	13.936
2016	13.418
2017	13.398
2018	13.271
2019	13.179
2020	13.111
2021	13.048
2022	13.003