Year	Percent
1990	63.872
1991	63.617
1992	63.501
1993	63.445
1994	63.323
1995	63.096
1996	64.057
1997	65.083
1998	66.193
1999	67.481
2000	68.976
2001	71.254
2002	73.483
2003	75.477
2004	77.093
2005	78.303
2006	79.133
2007	79.711
2008	80.068
2009	80.281
2010	79.291
2011	78.181
2012	82.109
2013	75.022
2014	69.979
2015	75.047
2016	74.793
2017	75.185
2018	75.584
2019	75.982
2020	76.376
2021	76.765
2022	77.154
2023	77.544
2024	77.939
2025	78.344
2026	78.756
2027	79.178
2028	79.607
2029	80.037
2030	80.463