Year	Percent
1991	53.879
1992	53.646
1993	53.601
1994	53.254
1995	52.832
1996	52.412
1997	51.595
1998	52.17
1999	52.735
2000	52.79
2001	52.739
2002	52.676
2003	52.479
2004	51.801
2005	51.565
2006	51.38
2007	51.156
2008	50.902
2009	50.649
2010	51.092
2011	51.952
2012	54.784
2013	53.149
2014	53.83
2015	53.014
2016	50.594
2017	50.969
2018	51.372
2019	51.779
2020	52.155
2021	52.485
2022	52.782