Year	Percent
1991	53.687
1992	55.269
1993	56.726
1994	58.434
1995	59.348
1996	60.76
1997	62.06
1998	63.86
1999	65.139
2000	66.317
2001	66.303
2002	67.124
2003	67.562
2004	68.037
2005	68.693
2006	69.295
2007	69.348
2008	69.547
2009	70.421
2010	70.454
2011	70.588
2012	71.035
2013	71.191
2014	71.348
2015	71.617
2016	71.785
2017	72.317
2018	72.757
2019	73.257
2020	73.755
2021	74.18
2022	74.573