Year	Percent
1991	94.433
1992	94.048
1993	94.004
1994	93.877
1995	93.424
1996	92.45
1997	93.114
1998	93.301
1999	93.097
2000	91.761
2001	92.146
2002	91.986
2003	92.192
2004	91.253
2005	91.479
2006	91.521
2007	92.157
2008	91.384
2009	91.445
2010	91.146
2011	91.321
2012	91.334
2013	91.216
2014	90.898
2015	91.626
2016	92.233
2017	92.235
2018	92.238
2019	92.228
2020	92.212
2021	92.194
2022	92.181