Year	% of population
1984	74.2
1987	74.3
1990	62.8
1993	62.1
1996	53.2
1998	69.1
1999	50.8
2000	49.8
2001	48
2002	41.4
2003	40.9
2004	41.3
2005	40.4
2006	43
2007	40.7
2008	40.1
2009	38.5
2010	37.5
2011	36.7
2012	35.9
2013	34.8
2014	34.1
2015	32.3
2016	32.6
2017	31
2018	30.1
2019	29.2
2020	28.8
2021	28.1
2022	26.5
2023	25.7