Year	per 1000 people
1960	0.011
1965	0.016
1970	0.017
1975	0.016
1984	0.025
1990	0.018
1992	0.027
1994	0.023
1996	0.024
1997	0.035
1998	0.033
2002	0.033
2004	0.023
2008	0.019
2010	0.019