Year	Percent
1991	50.826
1992	51.732
1993	53.053
1994	59.028
1995	56.107
1996	60.159
1997	49.952
1998	45.753
1999	39.971
2000	31.878
2001	31.016
2002	29.895
2003	28.722
2004	30.086
2005	28.857
2006	28.226
2007	27.185
2008	26.558
2009	22.688
2010	21.621
2011	20.809
2012	21.296
2013	20.238
2014	17.527
2015	16.678
2016	18.621
2017	18.563
2018	18.04
2019	17.585
2020	17.153
2021	16.718
2022	16.321