Year	Percent
1991	68.503
1992	68.78
1993	68.049
1994	70.073
1995	68.131
1996	68.396
1997	68.305
1998	69.917
1999	68.662
2000	68.663
2001	68.81
2002	68.896
2003	70.882
2004	70.342
2005	70.395
2006	71.043
2007	71.212
2008	70.715
2009	70.222
2010	69.691
2011	69.478
2012	67.689
2013	67.684
2014	69.178
2015	69.38
2016	69.335
2017	69.93
2018	70.193
2019	70.575
2020	70.886
2021	71.179
2022	71.409