Year	Percent
1991	76.309
1992	76.304
1993	76.565
1994	76.508
1995	76.51
1996	76.673
1997	76.739
1998	76.743
1999	76.786
2000	76.831
2001	76.885
2002	76.878
2003	76.766
2004	76.395
2005	76.088
2006	76.098
2007	76.012
2008	75.852
2009	75.631
2010	75.276
2011	75.152
2012	74.907
2013	74.636
2014	74.32
2015	74.023
2016	73.848
2017	73.732
2018	73.64
2019	73.565
2020	73.51
2021	73.464
2022	73.426