Year per 1,000 people 1990 6.72 1991 6.46 1992 6.2 1993 5.94 1994 5.68 1995 5.42 1996 5.16 1997 4.9 1998 4.8 1999 4.6 2000 4.5 2001 4.4 2002 4.3 2003 4.2 2004 4.1 2005 4 2006 3.9 2007 3.675 2008 3.566 2009 3.554 2010 3.484 2011 3.459 2012 3.436 2013 3.309 2014 3.829 2015 3.304 2016 3.302 2017 3.26 2018 3.317 2019 3.225 2020 3.489 2021 3.815 2022 3.854