Year	Percent
1991	27.997
1992	30.008
1993	31.425
1994	31.543
1995	31.07
1996	31.131
1997	31.162
1998	26.572
1999	33.798
2000	33.899
2001	28.217
2002	28.295
2003	28.402
2004	27.253
2005	26.429
2006	26.327
2007	24.948
2008	24.718
2009	25.157
2010	24.858
2011	26.375
2012	26.108
2013	25.301
2014	25.574
2015	24.8
2016	24.731
2017	25.224
2018	25.032
2019	24.731
2020	24.314
2021	23.781
2022	23.163