Year	per 1000 people
1960	0.1
1965	0.125
1970	0.169
1975	0.169
1980	0.271
1981	0.275
1986	0.461
1990	0.537
1991	0.535
1992	0.593
1993	0.598
1994	0.597
1995	0.654
1996	0.667
1997	0.689
1998	0.718
1999	0.744
2000	0.767
2001	0.794
2002	0.807
2003	0.824
2004	1.331
2005	0.933
2007	1.025
2008	1.108
2010	1.222
2014	1.269
2015	1.289