Year	Percent
1991	52.806
1992	51.869
1993	52.136
1994	51.441
1995	52.164
1996	53.305
1997	53.094
1998	54.143
1999	54.198
2000	54.603
2001	55.239
2002	56.251
2003	57.838
2004	57.604
2005	58.928
2006	58.607
2007	59.496
2008	59.599
2009	63.509
2010	63.345
2011	63.18
2012	63.233
2013	65.221
2014	65.316
2015	65.804
2016	67.768
2017	69.284
2018	71.294
2019	72.222
2020	73.082
2021	74.143
2022	74.977