Year % 2000 4.735845 2001 5.379385 2002 4.413824 2003 3.869537 2004 4.954501 2005 4.539374 2006 4.408581 2007 4.164218 2008 4.166736 2009 5.306196 2010 4.310875 2011 4.127589 2012 4.304074 2013 3.993419 2014 4.051143 2015 4.061562 2016 3.539188 2017 4.410281 2018 4.316236 2019 4.235533 2020 29.25539 2021 0.0354198