Year	Percent
1991	29.304
1992	29.223
1993	28.862
1994	28.751
1995	28.406
1996	29.152
1997	29.37
1998	30.473
1999	31.231
2000	31.03
2001	32.301
2002	32.751
2003	34.015
2004	33.939
2005	32.588
2006	31.51
2007	30.595
2008	29.73
2009	28.05
2010	27.27
2011	26.541
2012	24.617
2013	24.522
2014	23.928
2015	27.542
2016	27.998
2017	31.224
2018	31.884
2019	32.429
2020	33.025
2021	33.606
2022	34.18