Year	Percent
1991	59.795
1992	52.863
1993	42.935
1994	41.406
1995	42.564
1996	41.83
1997	40.891
1998	43.526
1999	45.432
2000	46.674
2001	44.911
2002	42.139
2003	41.946
2004	37.436
2005	42.559
2006	40.775
2007	42.817
2008	42.482
2009	39.111
2010	39.288
2011	41.019
2012	41.515
2013	43.202
2014	44.62
2015	46.355
2016	46.791
2017	46.696
2018	46.712
2019	46.262
2020	45.557
2021	45.047
2022	44.794