Year	per 1000 people
1980	2.839
1985	3.304
1986	3.44
1987	3.527
1988	3.55
1989	3.6
1990	3.614
1991	3.673
1992	3.589
1993	3.57
1994	3.535
1995	3.17
1996	3.222
1997	3.171
2002	4.355
2006	2.49
2007	2.438
2010	2.295
2011	2.314
2012	2.279
2013	2.266
2014	2.291