Year % 2001 5.95 2002 7.62 2005 4.5 2007 3.5 2008 3.35 2009 2.13 2010 1.66 2011 1.67 2013 2.63 2015 1.14 2016 1.35 2017 1.43 2018 1.54 2021 1.72