Year	Percent
1990	84.005
1991	83.898
1992	84.673
1993	84.484
1994	84.393
1995	84.564
1996	84.402
1997	84.523
1998	84.34
1999	84.374
2000	84.171
2001	84.599
2002	83.8
2003	83.592
2004	84.644
2005	84.12
2006	83.573
2007	83.01
2008	82.432
2009	81.841
2010	81.235
2011	80.606
2012	79.956
2013	79.282
2014	78.578
2015	79.571
2016	79.29
2017	79.233
2018	79.173
2019	79.108
2020	79.033
2021	78.949
2022	78.859
2023	78.765
2024	78.671
2025	78.577
2026	78.482
2027	78.389
2028	78.298
2029	78.209
2030	78.121