Year	Percent
1990	79.635
1991	79.925
1992	79.162
1993	79.186
1994	79.568
1995	79.665
1996	79.788
1997	81.311
1998	82.202
1999	82.471
2000	83.845
2001	84.118
2002	84.67
2003	84.279
2004	83.889
2005	83.666
2006	83.936
2007	84.736
2008	85.381
2009	85.338
2010	83.753
2011	83.174
2012	83.821
2013	84.19
2014	84.128
2015	84.569
2016	84.404
2017	84.362
2018	84.312
2019	84.268
2020	84.237
2021	84.211
2022	84.194
2023	84.189
2024	84.193
2025	84.207
2026	84.223
2027	84.246
2028	84.277
2029	84.31
2030	84.345