Year	per 1000 people
1960	0.235
1970	0.312
1980	0.36
1984	0.458
1990	0.686
1991	0.683
1992	0.75
1993	0.765
1994	0.921
1995	1.073
1996	1.106
1997	1.094
1998	1.036
1999	1.024
2000	1.095
2001	1.06