Year	Percent
1991	53.394
1992	56.457
1993	58.537
1994	59.155
1995	62.119
1996	61.658
1997	61.549
1998	61.266
1999	59.044
2000	59.698
2001	60.823
2002	60.992
2003	61.581
2004	61.754
2005	61.618
2006	61.838
2007	61.867
2008	61.893
2009	61.925
2010	62.435
2011	62.584
2012	62.774
2013	63.278
2014	62.684
2015	62.229
2016	61.966
2017	61.827
2018	61.764
2019	61.666
2020	61.51
2021	61.276
2022	60.986