1997 1997 Post election study – POL 1997 Post election study – EN 2001 2001 Post election study – POL 2001 Post election study – EN 2005 2005 Post election study – POL – W1 2005 Post election study – POL – W2 2007 2007 Post election study – POL 2007 Post election study – EN 2015 2015 Post election study – POL
