Season 1 NBC , 2004 - 2005 Watch now Season 2 NBC , 2005 Season 3 NBC , 2006 Season 4 NBC , 2007 Season 5 NBC , 2008 Season 6 NBC , 2008 Season 7 NBC , 2009 Season 8 NBC , 2009 Season 9 NBC , 2010 Season 10 NBC , 2010 Season 11 NBC , 2011 Season 12 NBC , 2011 Season 13 NBC , 2012 Season 14 NBC , 2013 Season 15 NBC , 2013 - 2014 Season 16 NBC , 2014 - 2015 Season 17 NBC , 2016 Season 18 USA Network , 2020
, 2004 - 2005
, 2013 - 2014
, 2014 - 2015
