Year	Percent
1991	46.872
1992	48.753
1993	49.742
1994	50.686
1995	51.273
1996	49.006
1997	48.923
1998	48.797
1999	48.682
2000	49.719
2001	51.214
2002	52.636
2003	54.002
2004	55.414
2005	56.564
2006	57.916
2007	59.348
2008	59.191
2009	57.807
2010	57.14
2011	56.845
2012	57.38
2013	57.677
2014	58.307
2015	58.849
2016	59.243
2017	59.507
2018	59.397
2019	59.251
2020	59.067
2021	58.834
2022	58.558