Year	Percent
1990	76.266
1991	76.216
1992	76.054
1993	75.424
1994	74.028
1995	72.916
1996	72.302
1997	71.512
1998	70.853
1999	69.981
2000	70.345
2001	70.931
2002	70.33
2003	69.889
2004	69.855
2005	70.642
2006	70.031
2007	70.008
2008	70.887
2009	71.728
2010	72.33
2011	72.815
2012	73.445
2013	74.016
2014	74.778
2015	75.037
2016	75.879
2017	76.054
2018	76.206
2019	76.316
2020	76.372
2021	76.38
2022	76.324
2023	76.218
2024	76.091
2025	75.967
2026	75.852
2027	75.744
2028	75.642
2029	75.536
2030	75.422
