Year	Percent
1991	14.94
1992	14.9
1993	13.867
1994	13.736
1995	14.555
1996	12.731
1997	13.091
1998	12.545
1999	12.638
2000	12.433
2001	12.741
2002	12.639
2003	13.772
2004	12.861
2005	13.892
2006	15.272
2007	16.316
2008	18.424
2009	18.434
2010	20.168
2011	21.885
2012	23.955
2013	26.045
2014	26.692
2015	26.48
2016	24.422
2017	24.543
2018	24.961
2019	25.404
2020	25.694
2021	25.855
2022	26.17