Year	per 1000 people
1960	0.441
1970	0.35
1980	0.361
1981	0.404
1986	0.28
1989	0.207
1992	0.365
1996	0.344
1998	0.33
1999	0.691
2003	0.281
2005	0.278
2008	0.463
2010	0.344