Year	Percent
1991	40.668
1992	40.383
1993	40.873
1994	40.369
1995	40.3
1996	40.365
1997	42.201
1998	43.638
1999	42.808
2000	46.281
2001	49.87
2002	51.774
2003	52.891
2004	53.511
2005	54.773
2006	55.177
2007	55.554
2008	55.628
2009	55.177
2010	56.818
2011	56.811
2012	57.573
2013	57.796
2014	57.812
2015	52.561
2016	51.171
2017	44.125
2018	41.522
2019	46.452
2020	48.545
2021	49.101
2022	49.771