Year	% of population
1990	23.2
1991	23.7
1992	25
1993	26.3
1994	28.1
1995	27.9
1996	28.1
1997	26.6
1998	26.7
1999	29
2000	28.4
2001	27.4
2002	26.4
2003	26.2
2004	24.7
2005	23.4
2006	21.9
2007	20.4
2008	19.1
2009	18.7
2010	18.2
2011	17.8
2012	17.7
2013	17.3
2014	17.5
2015	17
2016	17
2017	16.6
2018	15.9
2019	15.9
2020	15.5
2021	15.1
2022	15.1