Year	per 1000 people
1970	0.513
1981	0.738
1986	1.676
1990	1.5
1996	1.26
1997	1.26
2001	2.217
2005	2.569
2006	2.34
2008	3.319
2009	3.222
2010	3.919
2014	1.964