Year % 1986 1.8 1990 2.1 1994 2.2 1998 2.1 2005 2 2006 2 2009 2 2011 2.9 2012 3 2013 3.1 2014 2.8 2015 2.9 2016 2.8 2017 2.7 2018 2.7 2019 2.8 2020 2.8 2021 2.7 2022 2.8