Year	Percent
1990	70.183
1991	70.268
1992	71.056
1993	71.624
1994	71.874
1995	71.892
1996	71.813
1997	71.675
1998	71.472
1999	71.256
2000	70.262
2001	69.272
2002	68.334
2003	67.467
2004	66.694
2005	66.02
2006	65.41
2007	64.883
2008	65.517
2009	66.165
2010	66.811
2011	67.344
2012	67.639
2013	67.964
2014	68.362
2015	68.682
2016	69.714
2017	69.478
2018	69.192
2019	68.862
2020	68.492
2021	68.05
2022	67.582
2023	67.08
2024	66.533
2025	65.938
2026	65.276
2027	64.571
2028	63.87
2029	63.243
2030	62.731