Year % 1990 3.5 1993 3.3 1996 3.1 1999 2.7 2002 2.3 2005 2.4 2008 2.1 2010 2 2011 2.1 2012 2.1 2013 2.5 2014 2.5 2015 2.6 2016 2.7 2017 2.6 2018 2.7 2019 2.8 2020 3.1