Year	Percent
1991	51.804
1992	51.184
1993	50.946
1994	51.888
1995	52.365
1996	52.997
1997	52.947
1998	53.216
1999	53.224
2000	51.029
2001	50.631
2002	50.559
2003	50.941
2004	50.877
2005	50.913
2006	50.629
2007	50.965
2008	51.044
2009	50.807
2010	50.969
2011	50.744
2012	50.635
2013	50.337
2014	50.277
2015	50.525
2016	50.504
2017	50.067
2018	49.847
2019	49.662
2020	49.412
2021	49.055
2022	48.684