Year	Percent
1990	82.428
1991	82.546
1992	82.634
1993	82.845
1994	83.141
1995	83.333
1996	81.922
1997	80.496
1998	79.563
1999	79.177
2000	78.774
2001	78.664
2002	78.91
2003	79.246
2004	79.334
2005	79.385
2006	78.964
2007	79.286
2008	80.017
2009	81.335
2010	82.923
2011	84.15
2012	85.107
2013	86.388
2014	87.691
2015	88.697
2016	88.514
2017	88.617
2018	89.04
2019	89.667
2020	90.328
2021	89.864
2022	89.347
2023	88.877
2024	88.546
2025	88.365
2026	87.798
2027	87.307
2028	86.938
2029	86.699
2030	86.555