Year	Percent
1991	35.489
1992	34.782
1993	34.275
1994	33.472
1995	33.164
1996	34.287
1997	34.423
1998	33.426
1999	33.866
2000	34.636
2001	33.973
2002	34.889
2003	35.816
2004	36.56
2005	36.071
2006	35.255
2007	34.237
2008	34.027
2009	32.644
2010	33.862
2011	33.964
2012	33.294
2013	33.177
2014	32.344
2015	33.172
2016	34.276
2017	35.872
2018	36.391
2019	36.572
2020	36.4
2021	36.196
2022	36.038