Year	Percent
1990	78.888
1991	78.939
1992	79.004
1993	79.112
1994	79.127
1995	79.097
1996	78.997
1997	78.765
1998	78.485
1999	76.918
2000	74.883
2001	74.071
2002	74.219
2003	75.548
2004	73.445
2005	72.324
2006	70.639
2007	71.222
2008	71.592
2009	71.745
2010	72.052
2011	73.656
2012	73.789
2013	74.756
2014	75.974
2015	75.754
2016	77.053
2017	77.23
2018	77.385
2019	77.491
2020	77.527
2021	77.49
2022	77.374
2023	77.186
2024	76.952
2025	76.687
2026	76.395
2027	76.065
2028	75.711
2029	75.356
2030	75.022