Year	Percent
1991	36.264
1992	36.401
1993	36.441
1994	35.876
1995	36.777
1996	36.335
1997	36.315
1998	36.713
1999	36.816
2000	35.686
2001	36.618
2002	37.403
2003	37.973
2004	39.253
2005	40.411
2006	41.863
2007	42.677
2008	41.861
2009	41.873
2010	42.607
2011	42.851
2012	43.578
2013	44.555
2014	44.988
2015	45.112
2016	45.172
2017	45.323
2018	46.204
2019	47.167
2020	48.071
2021	49.065
2022	49.989