Year	per 1000 people
1960	0.375
1970	0.256
1980	0.362
1981	0.602
1982	0.6
1989	0.492
1991	0.508
1997	0.44
2000	0.499
2001	0.356
2002	0.303
2007	0.563
2008	0.554
2009	0.599
2010	0.558