Year	Percent
1991	48.06155
1992	48.60641
1993	49.04615
1994	49.37163
1995	49.83802
1996	50.22164
1997	50.8722
1998	50.98726
1999	50.33784
2000	50.22209
2001	49.69728
2002	49.44246
2003	49.11001
2004	48.73291
2005	48.16373
2006	48.11526
2007	48.0297
2008	47.50233
2009	47.32613
2010	47.08819
2011	46.72577
2012	46.31436
2013	45.9163
2014	45.50848
2015	45.26548
2016	44.63181
2017	44.58112
2018	44.52724
2019	43.80895