Year 1 in: rate varies by country 2000 15 2001 15 2002 15 2003 16 2004 16 2005 16 2006 16 2007 16 2008 15 2009 15 2010 15 2011 17 2012 16 2013 16 2014 16 2015 17 2016 17 2017 17 2018 17 2019 17 2020 19