Year	Percent
1991	53.653
1992	55.797
1993	56.835
1994	56.399
1995	60.288
1996	61.196
1997	61.92
1998	62.404
1999	62.816
2000	61.156
2001	62.478
2002	60.971
2003	62.038
2004	62.691
2005	61.689
2006	63.04
2007	65.007
2008	64.623
2009	66.341
2010	66.184
2011	67.492
2012	69.73
2013	70.231
2014	70.556
2015	70.95
2016	71.584
2017	72.064
2018	72.371
2019	72.679
2020	72.952
2021	73.206
2022	73.454