Year	Percent
1990	77.997
1991	77.337
1992	76.62
1993	75.835
1994	74.974
1995	74.039
1996	73.141
1997	72.179
1998	71.193
1999	70.239
2000	69.356
2001	69.344
2002	69.41
2003	69.537
2004	69.703
2005	69.894
2006	70.071
2007	70.225
2008	70.519
2009	70.701
2010	71.298
2011	71.378
2012	71.572
2013	71.695
2014	71.877
2015	72.128
2016	72.397
2017	72.645
2018	72.881
2019	73.098
2020	73.291
2021	73.493
2022	73.677
2023	73.844
2024	74.002
2025	74.154
2026	74.329
2027	74.503
2028	74.671
2029	74.828
2030	74.97