Year	Percent
1991	27.724
1992	27.529
1993	29.217
1994	29.562
1995	27.919
1996	25.608
1997	25.958
1998	30.327
1999	29.744
2000	29.491
2001	27.45
2002	28.316
2003	30.333
2004	28.59
2005	28.055
2006	29.558
2007	28.439
2008	28.54
2009	27.605
2010	27.172
2011	28.47
2012	29.044
2013	29.056
2014	29.157
2015	28.65
2016	28.366
2017	28.53
2018	28.689
2019	28.801
2020	28.845
2021	28.824
2022	28.72