Year	per 1000 people
1960	0.215
1965	0.255
1970	0.24
1975	0.235
1980	0.521
1981	0.552
1985	0.529
1989	0.858
1990	0.811
1991	0.835
1992	0.847
1993	0.844
1994	0.845
1995	0.85
2004	1.072
2007	1.156
2008	1.171
2009	1.187
2010	1.202
2011	1.246
2012	1.368
2013	1.619
2014	1.915
2015	2.003