Year	Percent
1991	48.877
1992	50.949
1993	49.511
1994	50.032
1995	49.838
1996	50.21
1997	48.626
1998	43.705
1999	44.55
2000	44.015
2001	45.509
2002	45.044
2003	45.216
2004	47.387
2005	48.259
2006	48.348
2007	47.91
2008	49.293
2009	50.331
2010	51.022
2011	51.616
2012	52.657
2013	55.488
2014	56.959
2015	57.455
2016	57.688
2017	57.452
2018	57.777
2019	58.118
2020	58.407
2021	58.728
2022	58.935