Year % of total labor force 2006 6.660006660006661 2007 6.230684876881667 2008 6.215761513662244 2009 5.444442157690013 2010 5.367046237653004 2011 4.981472847292092 2012 4.835348061692372 2013 4.81443857242805 2014 4.565422732656641 2015 4.424275134839423 2016 4.353842763046172 2017 4.318472987951461 2018 4.335036926792283 2019 4.108210258201015 2020 4.426100715921791