Year	per 1000 people
1960	0.534
1965	0.533
1970	0.435
1975	0.439
1979	0.563
1981	0.579
1984	0.701
1985	0.675
1988	0.64
1990	0.65
1991	0.813
1994	0.28
1995	0.73
1997	1.098
2000	1.17
2002	1.154
2012	1.286