Year	Percent
1991	56.102
1992	55.49
1993	56.521
1994	58.029
1995	60.55
1996	61.261
1997	61.216
1998	61.148
1999	61.012
2000	60.642
2001	60.341
2002	58.912
2003	59.187
2004	59.127
2005	58.843
2006	58.856
2007	59.964
2008	60.277
2009	61.065
2010	60.273
2011	58.95
2012	58.295
2013	57.17
2014	57.442
2015	56.724
2016	55.505
2017	55.551
2018	55.611
2019	55.628
2020	55.589
2021	55.512
2022	55.388