Year per 1,000 uninfected population ages 15-49 1990 2.9 1991 3.5 1992 4.2 1993 5 1994 5.5 1995 5.9 1996 6.2 1997 6.2 1998 6 1999 5.4 2000 5.1 2001 4.6 2002 4.1 2003 3.8 2004 3.6 2005 3.3 2006 3.1 2007 3 2008 2.9 2009 2.9 2010 2.7 2011 2.6 2012 2.5 2013 2.3 2014 2.1 2015 2 2016 1.8 2017 1.6 2018 1.5