Year	Percent
1990	47.733
1991	48.016
1992	47.924
1993	47.253
1994	47.361
1995	47.471
1996	49.421
1997	51.335
1998	53.191
1999	54.961
2000	55.384
2001	55.936
2002	56.493
2003	57.179
2004	58.09
2005	58.699
2006	59.356
2007	60.129
2008	60.85
2009	61.479
2010	62.215
2011	62.869
2012	63.339
2013	63.776
2014	64.157
2015	64.426
2016	63.892
2017	64.23
2018	64.583
2019	64.927
2020	65.249
2021	65.556
2022	65.841
2023	66.119
2024	66.406
2025	66.715
2026	67.045
2027	67.392
2028	67.745
2029	68.086
2030	68.407