Year	Percent
1990	77.396
1991	77.505
1992	77.531
1993	77.449
1994	77.39
1995	77.359
1996	77.167
1997	77.041
1998	76.9
1999	76.861
2000	76.608
2001	76.509
2002	76.432
2003	76.059
2004	74.73
2005	75.249
2006	75.714
2007	76.133
2008	76.514
2009	76.862
2010	77.185
2011	77.478
2012	77.753
2013	78.007
2014	77.918
2015	77.967
2016	78.248
2017	78.318
2018	78.382
2019	78.436
2020	78.474
2021	78.491
2022	78.497
2023	78.489
2024	78.465
2025	78.425
2026	78.364
2027	78.292
2028	78.214
2029	78.139
2030	78.071