Year	Percent
1991	85.276
1992	85.367
1993	85.448
1994	85.52
1995	85.556
1996	85.499
1997	85.537
1998	85.533
1999	85.501
2000	85.545
2001	85.522
2002	85.516
2003	85.461
2004	85.461
2005	85.401
2006	85.379
2007	85.293
2008	85.217
2009	85.152
2010	85.074
2011	85.005
2012	84.899
2013	84.806
2014	84.708
2015	84.717
2016	84.801
2017	84.765
2018	84.736
2019	84.711
2020	84.676
2021	84.647
2022	84.589