Year	% of population
1975	7.2
1981	8.7
1987	6.7
1992	7.7
1995	8.7
2000	7.2
2001	7
2002	7.5
2003	8.9
2004	8.1
2005	9.8
2006	8.8
2007	9.2
2008	10
2009	10.4
2010	10
2011	10.5
2012	10.8
2013	11.5
2014	10.5
2015	10.9
2016	11.5
2017	11
2018	11.7
2019	11.4
2020	11
2021	12.1