Year	Percent
1991	46.231
1992	45.623
1993	45.162
1994	46.611
1995	48.053
1996	51.061
1997	53.11
1998	54.925
1999	54.233
2000	53.615
2001	54.63
2002	55.547
2003	56.39
2004	57.178
2005	57.909
2006	57.225
2007	56.468
2008	56.461
2009	51.547
2010	46.323
2011	49.02
2012	50.31
2013	49.748
2014	49.139
2015	48.492
2016	47.877
2017	47.58
2018	47.303
2019	47.037
2020	46.784
2021	46.544
2022	46.313