Year	per 1,000 people
1960	9
1970	12.5
1980	13.6999998092651
1985	14.6999998092651
1993	15.6000003815
1994	15.5
1995	15.3999996185
1996	15.1999998093
1997	15.1000003815
1998	15
1999	14.8000001907
2000	14.69
2001	14.58
2002	14.43
2003	14.26
2004	14.2
2005	14.08
2006	13.97
2007	13.87
2008	13.71
2009	13.62
2010	13.51
2011	13.4
2012	13.35
2013	13.3
2014	13.21
2015	13.17
2016	13.11
2017	13.05
2018	12.98