Year % 2001 21.65967 2002 22.22178 2004 19.77547 2005 19.29652 2006 19.13637 2007 19.16579 2008 29.578 2009 28.86348 2010 19.45147 2011 27.41918 2012 17.18248 2013 20.50685 2014 28.40064 2015 30.12933 2016 30.70615 2017 16.36822 2018 9.338254 2019 19.61719 2020 21.93281 2021 22.13893