Year	Percent
1991	49.295
1992	55.31
1993	61.927
1994	64.872
1995	65.184
1996	66.873
1997	66.406
1998	65.71
1999	66.011
2000	69.551
2001	65.705
2002	68.682
2003	71.139
2004	73.839
2005	76.706
2006	81.729
2007	85.464
2008	87.911
2009	91.35
2010	92.862
2011	93.955
2012	94.789
2013	95.344
2014	94.712
2015	93.15
2016	92.624
2017	89.893
2018	90.162
2019	90.367
2020	90.48
2021	90.583
2022	90.686