Year	% of population
1985	7.7
1986	8.9
1987	10.2
1988	8.4
1989	7.5
1990	7.7
1991	8.2
1992	7.6
1993	6.5
1994	9.5
1995	9.2
1996	10.2
1997	10.2
1998	11.2
1999	11.5
2000	11
2001	10.2
2002	8.8
2003	10.9
2004	11.2
2005	11.3
2006	11.2
2007	11.1
2008	12.5
2009	13
2010	11.3
2011	14.2
2012	13.4
2013	13.8
2014	12.1
2015	13.3
2016	12.5
2017	14.4
2018	15.3
2019	13.9
2020	15
2021	13.4