0 1 10 Sample assessments during 2007-W20 Sample assessments during 2005-W20 Sample assessments during 2008-W20 Sample assessments during 2009-W20 Sample assessments during 2010-W20 Sample assessments during 2006-W20 Sample assessments during 2011-W20 Sample assessments during 2012-W20 Sample assessments during 2013-W20 Sample assessments during 2001-W20