Year	ages 15+
1990	660
1991	940
1992	1200
1993	1600
1994	2000
1995	2300
1996	2600
1997	2800
1998	2900
1999	3000
2000	2900
2001	2900
2002	2900
2003	2900
2004	2800
2005	2700
2006	2600
2007	2600
2008	2600
2009	2500
2010	2500
2011	2400
2012	2300
2013	2200
2014	2200
2015	2100
2016	2000
2017	1900
2018	1900