Year % of population ages 15-49 1990 4.3 1991 4.5 1992 4.7 1993 4.7 1994 4.7 1995 4.7 1996 4.6 1997 4.5 1998 4.4 1999 4.3 2000 4.2 2001 4 2002 3.9 2003 3.8 2004 3.7 2005 3.7 2006 3.6 2007 3.5 2008 3.5 2009 3.5 2010 3.5 2011 3.5 2012 3.5 2013 3.6 2014 3.6 2015 3.6 2016 3.7 2017 3.7 2018 3.8 2019 3.9 2020 4 2021 4 2022 4.1