Year	Percent
1991	63.033
1992	63.328
1993	63.53
1994	64.133
1995	64.932
1996	66.737
1997	66.931
1998	66.507
1999	67.199
2000	57.323
2001	69.647
2002	70.542
2003	70.597
2004	71.6
2005	73.489
2006	72.549
2007	72.331
2008	71.448
2009	61.856
2010	62.591
2011	74.431
2012	74.94
2013	76.156
2014	78.205
2015	78.665
2016	79.783
2017	79.763
2018	79.882
2019	80.015
2020	80.146
2021	80.292
2022	80.448