Year	per 1000 people
1960	0.51
1965	0.605
1970	0.521
1975	0.526
1979	0.692
1980	0.716
1981	0.76
1982	0.846
1983	0.902
1984	0.908
1985	0.929
1986	0.984
1987	0.983
1988	0.965
1989	1.035
1990	1.064
1992	1.03
1995	0.98
1997	0.932
1999	1.166
2009	0.94
2010	0.92
2012	1.116