Year	% of population
1996	28.1
1997	35.8
1998	35.4
1999	37.3
2000	38.7
2001	38.7
2002	32.6
2003	33.3
2004	32
2005	33.3
2006	32.6
2007	33.8
2008	32.9
2009	32.5
2010	33.7
2011	32.4
2012	32
2013	30.2
2014	28.5
2015	27.9
2016	27
2017	28.3
2018	27.6
2019	26.7
2020	27.9
2021	27.1