Year	Percent
1991	63.047
1992	63.024
1993	62.954
1994	62.91
1995	62.958
1996	63.569
1997	64.299
1998	64.962
1999	65.703
2000	66.386
2001	67.113
2002	66.825
2003	66.546
2004	66.261
2005	65.936
2006	66.356
2007	67.454
2008	67.503
2009	67.488
2010	67.52
2011	67.501
2012	67.485
2013	67.46
2014	67.429
2015	67.393
2016	67.361
2017	67.332
2018	67.309
2019	67.29
2020	67.273
2021	67.257
2022	67.244