Year	Percent
1991	42.441
1992	44.196
1993	40.71
1994	38.739
1995	47.682
1996	46.763
1997	47.134
1998	47.941
1999	47.184
2000	49.916
2001	50.423
2002	48.69
2003	41.774
2004	40.072
2005	40.176
2006	32.012
2007	30.071
2008	28.356
2009	24.826
2010	24.449
2011	24.106
2012	23.205
2013	25.381
2014	26.592
2015	29.727
2016	30.306
2017	29.868
2018	29.124
2019	28.385
2020	27.629
2021	26.895
2022	26.194