Year	Percent
1991	42.272
1992	40.432
1993	41.772
1994	43.516
1995	44.214
1996	42.056
1997	43.169
1998	44.049
1999	42.238
2000	45.904
2001	44.196
2002	45.726
2003	46.592
2004	48.731
2005	49.287
2006	49.893
2007	50.813
2008	48.691
2009	48.344
2010	47.404
2011	46.952
2012	48.377
2013	47.641
2014	46.506
2015	49.84
2016	52.542
2017	52.685
2018	52.184
2019	51.681
2020	51.175
2021	50.674
2022	50.173