Year	Percent
1991	52.496
1992	51.278
1993	50.784
1994	50.203
1995	49.834
1996	50.327
1997	50.671
1998	49.526
1999	50.993
2000	51.628
2001	50.239
2002	47.882
2003	47.599
2004	47.359
2005	47.04
2006	46.62
2007	48.481
2008	39.9
2009	40.554
2010	38.702
2011	40.315
2012	41.577
2013	42.679
2014	41.939
2015	41.936
2016	41.932
2017	42.038
2018	42.051
2019	42.063
2020	42.025
2021	42.011
2022	41.994