Year	Percent
1991	42.849
1992	45.828
1993	45.302
1994	44.156
1995	44.042
1996	44.976
1997	43.099
1998	43.913
1999	40.589
2000	40.522
2001	40.376
2002	41.585
2003	41.433
2004	41.655
2005	39.802
2006	40.228
2007	45.119
2008	45.769
2009	44.055
2010	44.553
2011	45.348
2012	45.643
2013	44.379
2014	42.396
2015	44.482
2016	48.273
2017	48.416
2018	48.482
2019	48.512
2020	48.488
2021	48.377
2022	48.258