[['series', 'episodes', 'series premiere', 'series finale', 'region 1', 'region 2', 'region 4'], ['pilot', '1', '18 february 2008', '18 february 2008', 'n / a', 'n / a', 'n / a'], ['1', '6', '25 january 2009', '1 march 2009', '20 july 2010', '20 april 2009', '6 august 2009'], ['2', '8', '10 january 2010', '28 february 2010', '21 september 2010', '12 april 2010', '5 august 2010'], ['3', '8', '23 january 2011', '13 march 2011', '3 may 2011', '28 march 2011', '5 may 2011'], ['4', '8', '5 february 2012', '25 march 2012', '15 january 2013', '23 april 2012', '7 june 2012']]
there is an average of 8 Episode per season
there is an average of [ENT] [ENT] per season