Year	Percent
1991	75.038
1992	74.869
1993	74.217
1994	73.576
1995	72.917
1996	72.35
1997	71.783
1998	71.278
1999	69.754
2000	68.881
2001	69.964
2002	71.042
2003	72.118
2004	73.189
2005	74.259
2006	75.33
2007	75.191
2008	75.052
2009	74.885
2010	74.77
2011	75.604
2012	76.442
2013	77.754
2014	77.598
2015	77.467
2016	77.319
2017	77.459
2018	77.613
2019	77.748
2020	77.863
2021	77.965
2022	78.059