Year	Percent
1991	35.048
1992	35.872
1993	35.865
1994	36.032
1995	36.106
1996	35.645
1997	36.14
1998	36.042
1999	35.798
2000	35.878
2001	36.733
2002	38.753
2003	40.393
2004	43.193
2005	43.42
2006	45.303
2007	47.375
2008	47.894
2009	48.017
2010	49.748
2011	50.869
2012	52.553
2013	54.861
2014	56.774
2015	58.469
2016	57.99
2017	57.776
2018	57.535
2019	57.366
2020	57.263
2021	56.769
2022	56.415