Year	Percent
1991	61.274
1992	63.073
1993	63.801
1994	67.103
1995	68.271
1996	70.193
1997	72.315
1998	74.012
1999	75.797
2000	75.488
2001	75.396
2002	76.96
2003	78.059
2004	77.848
2005	80.098
2006	76.251
2007	75.83
2008	77.834
2009	75.615
2010	77.927
2011	79.229
2012	79.534
2013	81.016
2014	82.774
2015	83.677
2016	84.043
2017	85.39
2018	86.519
2019	87.203
2020	87.903
2021	88.512
2022	89