Year per 1,000 people 1970 1.9592076562929956 1975 2.241007957730109 1980 2.8120637672164257 1981 2.6894058695500234 1985 4.028523261287343 1986 4.071123396486504 1987 4.059296492390167 1988 4.175169551342641 1989 4.0120395516011085 1990 3.8841094577670376 1991 4.047720358029813 1992 3.9712948361849394 1993 3.9286612780668557 1994 3.9138711059399283 1995 3.8287423380203776 1996 3.669658077595942 1997 3.598719074795335 1998 3.695160500007606 1999 3.5592957773788596 2000 2.869907602693248 2001 2.791444019940283 2002 2.9105966628198776 2003 2.814612345001654 2004 2.9087044422749755 2005 2.863771278880085 2006 2.893056065846905 2007 2.923871702277348 2008 3.009019659927271 2009 3.0845921203405187 2010 3.2058163735364977 2011 3.2488601874589653 2012 3.5256334012762314 2013 3.6152257332333955 2014 3.7510969399006213 2015 3.862737122142699 2016 3.996901998718362 2017 4.188489934855361