Year	per 1000 people
1960	0.34
1965	0.378
1970	0.453
1975	0.46
1980	0.416
1981	0.426
1984	0.637
1988	0.471
1990	0.657
1995	0.82
1997	0.856
2003	0.39
2005	0.505
2006	0.498
2007	0.533
2008	0.657
2009	0.713
2010	0.739
2011	0.827
2012	0.876
2013	0.916
2014	0.914