Year % 1999 25.09047 2000 37.25713 2001 25.037 2002 25.32992 2004 24.67846 2005 24.42727 2006 21.10126 2007 25.03434 2014 24.69386 2015 25.59806 2016 25.59806 2017 24.50187 2018 26.25164 2019 26.10333 2020 25.05255