Year	Percent
1991	53.897
1992	53.77
1993	53.542
1994	53.613
1995	52.332
1996	53.589
1997	53.242
1998	50.793
1999	52.711
2000	51.484
2001	52.617
2002	52.152
2003	51.499
2004	51.427
2005	50.335
2006	51.761
2007	51.231
2008	49.322
2009	48.762
2010	48.183
2011	48.169
2012	48.309
2013	48.853
2014	49.08
2015	49.312
2016	49.608
2017	49.544
2018	49.397
2019	49.228
2020	50.719
2021	51.458
2022	51.48