Year	Percent
1991	33.995
1992	26.271
1993	20.354
1994	31.737
1995	33.667
1996	30.067
1997	30.581
1998	26.924
1999	20.725
2000	32.477
2001	30.261
2002	27.265
2003	24.283
2004	26.029
2005	26.134
2006	22.404
2007	23.228
2008	32.072
2009	29.438
2010	28.942
2011	26.457
2012	26.094
2013	28.35
2014	27.165
2015	24.638
2016	26.599
2017	26.693
2018	26.809
2019	26.757
2020	26.87
2021	26.815
2022	26.761