Year	Percent
1990	75.769
1991	74.778
1992	74.234
1993	73.67
1994	73.753
1995	73.947
1996	73.729
1997	73.181
1998	72.899
1999	72.456
2000	72.312
2001	72.096
2002	71.999
2003	71.702
2004	71.638
2005	72.188
2006	72.307
2007	72.598
2008	72.675
2009	72.331
2010	72.45
2011	72.246
2012	71.773
2013	71.421
2014	71.005
2015	71.164
2016	70.667
2017	70.522
2018	70.378
2019	70.225
2020	70.056
2021	69.865
2022	69.665
2023	69.461
2024	69.262
2025	69.07
2026	68.902
2027	68.746
2028	68.603
2029	68.472
2030	68.354