Year	Percent
1991	47.222
1992	47.765
1993	49.123
1994	50.362
1995	51.763
1996	53.348
1997	55.875
1998	56.595
1999	57.7
2000	57
2001	58.273
2002	61.128
2003	62.198
2004	64.708
2005	65.501
2006	65.313
2007	67.382
2008	68.401
2009	71.117
2010	70.663
2011	71.034
2012	71.403
2013	71.7
2014	71.925
2015	72.885
2016	73.216
2017	73.601
2018	74.311
2019	74.923
2020	75.471
2021	76.029
2022	76.524