Series 1 - 7
Now that we've had a look at each individual series, let's look at them all together.
As we can see from the above graph the regular ratings and AI for Doctor Who have not dropped significantly in the last three years. The biggest views came during the 2009 Specials (Series 4.5). However I don't believe we can always consider these ratings when performing an analysis as they are not regular episodes. These episodes were aired months apart, so families would have been more likely to sit down and view them as they'd be starved for content. With regular episodes they may wait longer to watch an episode, casual viewers perhaps even choosing to miss an episode completely, as there would be another the next week.
This graph shows better the trend of ratings and AI between Russell T Davies' era and Moffat's. It disregards the special episodes and instead focuses on the regular series. From it we can see that on average the show is generally doing just as well during Moffat's era as it did during RTD's, both in terms of ratings and AI. Ratings have fallen slightly, but it is not a new trend and one which also happened with RTD's first three series. It's also important to note that BBC iPlayer viewings, which do not get counted, have added up to 2 million live views for some episodes, so these figures may not be completely accurate.