Year	Percent
1991	65.305
1992	65.673
1993	66.191
1994	66.399
1995	66.449
1996	66.368
1997	65.779
1998	65.282
1999	72.826
2000	74.282
2001	72.474
2002	72.573
2003	74.119
2004	75.035
2005	75.168
2006	75.621
2007	75.346
2008	73.764
2009	71.852
2010	70.387
2011	69.419
2012	68.842
2013	68.596
2014	68.31
2015	68.977
2016	52.976
2017	52.991
2018	53.003
2019	53.015
2020	53.026
2021	53.037
2022	53.047