Year	Percent
1990	76.501
1991	76.269
1992	76.181
1993	73.908
1994	71.378
1995	68.733
1996	68.223
1997	66.581
1998	68.174
1999	69.602
2000	70.358
2001	70.233
2002	69.934
2003	71.066
2004	70.665
2005	72.07
2006	72.86
2007	72.91
2008	73.066
2009	73.306
2010	74.365
2011	74.276
2012	76.413
2013	77.083
2014	78.791
2015	79.562
2016	79.734
2017	80.075
2018	80.413
2019	80.746
2020	81.072
2021	81.387
2022	81.691
2023	81.985
2024	82.274
2025	82.558
2026	82.832
2027	83.096
2028	83.35
2029	83.595
2030	83.832