Season 1 NBC , 2010 Watch now Season 2 NBC , 2010 - 2011 Watch now Season 3 NBC , 2011 - 2012 Watch now Season 4 NBC , 2012 - 2013 Watch now Season 5 NBC , 2013 - 2014 Watch now Season 6 NBC , 2014 - 2015 Watch now
, 2010 - 2011
, 2011 - 2012
, 2012 - 2013
, 2013 - 2014
, 2014 - 2015
