Year	Percent
1990	81.14
1991	81.391
1992	81.752
1993	81.097
1994	80.255
1995	79.233
1996	77.678
1997	76.402
1998	75.479
1999	74.907
2000	76.982
2001	76.26
2002	75.968
2003	75.812
2004	75.764
2005	75.764
2006	75.343
2007	75.42
2008	75.492
2009	75.449
2010	76.175
2011	77.019
2012	78.457
2013	80.067
2014	80.72
2015	81.061
2016	81.295
2017	81.567
2018	81.92
2019	82.311
2020	82.69
2021	82.326
2022	81.959
2023	81.622
2024	81.344
2025	81.127
2026	80.676
2027	80.292
2028	79.98
2029	79.729
2030	79.521