Year	Percent
1991	28.898
1992	29.733
1993	32.332
1994	34.368
1995	35.323
1996	34.682
1997	33.971
1998	33.591
1999	32.27
2000	30.987
2001	31.131
2002	30.942
2003	32.351
2004	30.348
2005	29.671
2006	31.4
2007	32.185
2008	36.612
2009	37.429
2010	37.945
2011	34.11
2012	34.454
2013	34.666
2014	34.613
2015	34.615
2016	34.528
2017	34.831
2018	35.173
2019	35.325
2020	35.773
2021	36.26
2022	36.714