Year	Percent
1991	58.098
1992	57.842
1993	57.798
1994	57.76
1995	57.505
1996	55.985
1997	54.899
1998	54.372
1999	54.319
2000	54.445
2001	53.635
2002	53.011
2003	53.138
2004	53.622
2005	54.009
2006	53.872
2007	53.691
2008	53.391
2009	53.075
2010	52.75
2011	50.884
2012	51.581
2013	52.391
2014	53.31
2015	54.267
2016	55.352
2017	55.562
2018	54.825
2019	53.257
2020	51.235
2021	49.947
2022	50.001