Year	Percent
1990	80.162
1991	80.402
1992	80.607
1993	80.458
1994	80.515
1995	80.711
1996	80.276
1997	79.728
1998	79.802
1999	80.054
2000	79.82
2001	78.915
2002	79.568
2003	79.651
2004	76.207
2005	77.789
2006	78.278
2007	79.394
2008	79.611
2009	79.726
2010	79.902
2011	79.994
2012	80.313
2013	80.429
2014	79.925
2015	80.029
2016	80.668
2017	80.583
2018	80.464
2019	80.334
2020	80.209
2021	80.074
2022	79.939
2023	79.812
2024	79.702
2025	79.615
2026	79.538
2027	79.482
2028	79.452
2029	79.458
2030	79.504