Year	per 1000 people
1960	0.027
1965	0.021
1970	0.013
1981	0.019
1984	0.087
1989	0.023
1990	0.022
1993	0.028
2003	0.011
2004	0.021
2008	0.018
2009	0.018
2010	0.019