Year per 1,000 people 1970 1.8 1971 1.9 1972 1.9 1973 1.9 1974 2 1975 2 1976 2.1 1977 2.1 1978 2.1 1979 2.2 1990 2.722 1991 2.676 1992 2.681 1993 2.868 1994 2.936 1995 3.001 1996 2.99 1997 3.12 1998 3.039 1999 3.088 2000 3.381 2001 3.443 2002 3.492 2003 3.509 2004 3.499 2005 3.539 2006 3.551 2007 3.561 2008 3.557 2009 3.584 2010 3.599 2011 3.637 2012 3.675 2013 3.688 2014 3.9345 2015 3.9516 2016 4.0194 2017 4.0676 2018 4.074 2019 4.119 2020 4.16 2021 5.469