Year	Percent
1991	58.708
1992	58.368
1993	61.424
1994	62.493
1995	64.298
1996	65.897
1997	61.791
1998	63.618
1999	67.15
2000	68.287
2001	69.57
2002	72.367
2003	71.482
2004	72.575
2005	74.778
2006	75.208
2007	76.729
2008	76.83
2009	78.563
2010	80.686
2011	80.725
2012	81.137
2013	81.574
2014	82.678
2015	82.225
2016	81.604
2017	81.95
2018	82.482
2019	83.043
2020	83.581
2021	84.07
2022	84.522