Year	per 1,000 people
1960	0.5065566370524682
1970	0.5827559377143794
1975	0.6257610850331953
1980	0.7258447505394933
1981	0.7294921956536933
1985	0.7059534480760777
1987	0.7025375228005929
1991	0.7171524247684248
2000	0.6809681086049584
2001	0.6314537991266875
2002	0.6313515478561393
2003	0.8633992152323493
2005	0.4340753399405226
2006	0.5198512367456042
2007	0.4869896164700101
2008	0.435080329029094
2009	0.46165753829291856
2010	0.52861740464131
2011	0.6207191525445951
2012	0.5443192906458847
2013	0.5056077297682302
2014	0.5367134825725587
2015	0.5982603764797805
2016	0.5270946502020857
2017	0.5880580363262539