Year	per 1,000 people
1960	0.458986908197403
1970	0.604499995708466
1975	0.588199973106384
1980	0.769699990749359
1981	0.769400000572205
1985	0.769200026988983
1987	0.718200027942657
1991	0.7870000005
2000	0.65
2001	0.64
2002	0.63
2003	0.8999999762
2005	0.41
2006	0.42
2007	0.41
2008	0.41
2009	0.44
2010	0.47
2011	0.63
2012	0.49
2013	0.49
2014	0.52
2015	0.58
2016	0.48
2017	0.53