Year % 2000 31.107990472978283 2001 30.456795345987555 2002 29.954540074264578 2003 29.45550347666291 2004 28.92226907192243 2005 28.307615884084044 2006 27.68154271455039 2007 27.045363380680705 2008 26.451726960260608 2009 25.85938138028395 2010 25.320062713825546 2011 24.95341818076551 2012 24.675523950763843 2013 24.534822123448976 2014 24.43422249355456 2015 24.443399865411838 2016 24.523447562949467 2017 24.488753309197335 2018 24.458203618301777 2019 24.505552357412277