Year	Percent
1990	77.389
1991	77.336
1992	77.358
1993	77.522
1994	77.485
1995	77.383
1996	77.239
1997	75.883
1998	75.971
1999	74.987
2000	72.997
2001	72.64
2002	74.477
2003	73.517
2004	73.914
2005	74.037
2006	76.223
2007	78.081
2008	78.545
2009	76.871
2010	75.549
2011	76.203
2012	77.448
2013	76.857
2014	77.749
2015	78.847
2016	78.9
2017	79.004
2018	78.974
2019	78.847
2020	78.649
2021	78.399
2022	78.072
2023	77.702
2024	77.354
2025	77.071
2026	76.865
2027	76.761
2028	76.73
2029	76.719
2030	76.695