Year	Percent
1991	17.205
1992	17.837
1993	19.872
1994	19.784
1995	19.568
1996	19.831
1997	21.376
1998	19.334
1999	22.742
2000	21.219
2001	19.541
2002	18.828
2003	19.937
2004	19.922
2005	23.923
2006	23.154
2007	25.092
2008	27.094
2009	27.48
2010	26.401
2011	25.1
2012	27.452
2013	30.724
2014	28.548
2015	27.902
2016	28.527
2017	28.185
2018	27.895
2019	27.622
2020	27.326
2021	27.012
2022	26.685