The Waters of Mars Overnight Ratings

BARB have now revealed unofficial overnight ratings for last night's broadcast of the second Doctor Who 2009 special, The Waters of Mars. When the episode was broadcast across the United Kingdom and Ireland on BBC One and on BBC HD last night, it was watched by an estimated 9.1 million according to BARB. The episode was written by both Doctor Who lead writer Russell T Davies and Phil Ford, and starred David Tennant as The Doctor, and Lindsay Duncan as Adelaide. The ratings released today by BARB are not final and will change in final ratings expected to be released in two weeks. What do you think of these Doctor Who viewing figures?