Year	Percent
1991	34.832
1992	29.182
1993	28.804
1994	28.204
1995	27.529
1996	27.478
1997	25.251
1998	27.47
1999	25.717
2000	26.97
2001	25.38
2002	23.614
2003	24.49
2004	26.619
2005	26.175
2006	27.859
2007	27.493
2008	27.811
2009	27.168
2010	27.297
2011	25.222
2012	26.362
2013	26.581
2014	24.757
2015	25.54
2016	25.088
2017	25.073
2018	25.047
2019	25.024
2020	25.004
2021	24.984
2022	24.964