Year	Percent
1991	26.107
1992	25.855
1993	25.006
1994	24.809
1995	25.476
1996	26.218
1997	27.349
1998	28.153
1999	30.145
2000	32.314
2001	33.518
2002	35.179
2003	36.558
2004	37.995
2005	40.567
2006	42.065
2007	43.178
2008	43.291
2009	41.568
2010	41.121
2011	40.755
2012	39.464
2013	38.585
2014	39.057
2015	39.99
2016	41.119
2017	42.229
2018	43.631
2019	44.118
2020	44.201
2021	44.174
2022	44.08