Year 1 in: rate varies by country 2000 15 2001 15 2002 15 2003 15 2004 16 2005 17 2006 18 2007 18 2008 19 2009 20 2010 22 2011 23 2012 24 2013 25 2014 26 2015 27 2016 28 2017 32 2018 32 2019 33 2020 31