Year	Percent
1991	19.652
1992	20.899
1993	23.418
1994	24.137
1995	24.799
1996	24.56
1997	23.184
1998	22.432
1999	23.997
2000	23.413
2001	22.265
2002	22.209
2003	21.806
2004	18.929
2005	16.926
2006	16.171
2007	13.98
2008	10.192
2009	11.532
2010	11.436
2011	10.673
2012	11.416
2013	10.827
2014	11.688
2015	11.61
2016	10.535
2017	10.382
2018	10.082
2019	9.8
2020	9.614
2021	9.393
2022	9.206