Year	Percent
1991	49.408
1992	51.274
1993	51.886
1994	54.736
1995	56.596
1996	57.735
1997	59.341
1998	60.518
1999	62.316
2000	62.784
2001	62.501
2002	64.055
2003	65.197
2004	65.654
2005	66.249
2006	67.541
2007	68.022
2008	68.353
2009	70.083
2010	71.187
2011	71.235
2012	72.163
2013	72.925
2014	73.217
2015	73.14
2016	73.707
2017	73.865
2018	74.51
2019	75.129
2020	75.741
2021	76.361
2022	76.924