Year per 1,000 uninfected population ages 15-49 1990 2.7 1991 3.3 1992 4.1 1993 5 1994 5.8 1995 6.4 1996 7 1997 7.3 1998 7.3 1999 7.1 2000 6.5 2001 6 2002 5.5 2003 4.8 2004 4.5 2005 4.1 2006 3.8 2007 3.6 2008 3.4 2009 3.2 2010 3 2011 2.8 2012 2.6 2013 2.4 2014 2.3 2015 2.2 2016 2 2017 1.8 2018 1.6