Year	Percent
1991	52.268
1992	52.579
1993	54.09
1994	54.987
1995	55.583
1996	58.097
1997	57.004
1998	57.772
1999	61.275
2000	61.987
2001	61.361
2002	61.67
2003	65.599
2004	64.863
2005	65.523
2006	67.098
2007	66.788
2008	68.909
2009	69.287
2010	70.939
2011	73.728
2012	73.895
2013	73.491
2014	72.495
2015	74.645
2016	76.67
2017	77.406
2018	78.418
2019	79.266
2020	79.889
2021	80.325
2022	80.753