Year	per 1000 people
1960	0.682
1970	0.802
1980	0.916
1981	0.973
1986	1.393
1987	1.38
1990	1.564
1995	1.879
1996	2.55
1999	2.119
2007	2.016
2008	2.059
2009	2.121
2010	2.174
2011	2.265
2012	2.308
2013	2.412
2014	2.496