Year	Percent
1991	36.092
1992	31.335
1993	31.471
1994	32.059
1995	29.781
1996	30.275
1997	31.225
1998	32.442
1999	32.46
2000	33.534
2001	34.94
2002	37.644
2003	38.034
2004	39.286
2005	39.265
2006	38.941
2007	40.874
2008	39.701
2009	40.393
2010	45.135
2011	44.619
2012	40.232
2013	42.871
2014	43.832
2015	43.799
2016	43.154
2017	43.023
2018	43.22
2019	43.675
2020	44.21
2021	45.212
2022	46.242