The Appreciation Index (AI) is a measure of how much the audience enjoyed the programme. The score, out of a hundred, is compiled by a specially selected panel of around 5,000 people who go online and rate and comment on TV programmes.
Doctor Who scored higher than most of the Christmas Day output. The most appreciated programmes were Downton Abbey on ITV1 and Call the Midwife on BBC One, both of which scored 90.
Meanwhile, an additional 0.56 million watched The Snowmen when it was repeated on Boxing Day on BBC Three, where it achieved a 2.3% share of the total TV audience.