Year	Percent
1991	69.395
1992	70.805
1993	72.774
1994	72.964
1995	74.348
1996	74.531
1997	75.686
1998	74.861
1999	75.87
2000	76.996
2001	80.837
2002	82.41
2003	82.661
2004	81.293
2005	80.745
2006	83.325
2007	83.58
2008	82.231
2009	87.902
2010	87.274
2011	87.469
2012	86.645
2013	88.69
2014	87.184
2015	87.761
2016	88.474
2017	88.919
2018	89.063
2019	89.26
2020	89.364
2021	89.498
2022	89.7