Year	Percent
1991	61.126
1992	61.453
1993	61.934
1994	62.286
1995	62.694
1996	62.731
1997	63.055
1998	63.971
1999	64.507
2000	65.427
2001	65.159
2002	66.14
2003	67.073
2004	66.189
2005	65.537
2006	65.854
2007	67.452
2008	68.373
2009	69.048
2010	69.039
2011	70.037
2012	70.016
2013	71.825
2014	72.165
2015	71.793
2016	71.795
2017	71.736
2018	71.959
2019	72.23
2020	72.368
2021	72.524
2022	72.649