The Ratings For The Two Doctors

Not quite sure what to make of these viewing figures. Given that the UK only had 4 TV channels they seem a little low (though even in this 900 channel nirvana that we currently inhabit, i bet its the same type of viewer who watch now as watched then).

The AI figure seems a little on the low side - I mean I don't want to be critical of the data but even some of the weaker offerings in season 6 of Nu Who were punching out AI in the 80s. Are we really expected to accept that this was 20% less well-received than the new stories?