There are all sorts of reasons why it might be the case it seems we have to defend a narrow lead for significantly longer - 30% - than we have to chase a result. One of them might be conscious or unconscious bias in terms of making decisions about how much additional time there should be.
The only thing that the statistics confirm is that over the last 15 games on average we have been given less time to pursue a game where we need a goal than where we do not, and conversely the statistics show that for Liverpool over a similar period of time the position is precisely the opposite.
To my mind, the only thing that this is conclusive of is that the issue warrants greater analysis and thought. I get as annoyed by the point of view that assumes, without more, that the numbers amount to proof of bias as I do with the point blank refusal that it could in any way even be suggestive of bias. The numbers are consistent with bias: nothing more, nothing less. Statistical evidence can corroborate, or be consistent with many things but it will rarely be proof in and of itself. That said, the numbers for both City and Liverpool do appear to suggest a trend.
I think that trend is worth investigating further. If I had time I would look at other data points on refereeing decisions, such as yellow cards and such. I don't recall for instance a single occasion on which an opposition player has received a red card, which I think might be unusual at this stage of the season. (But maybe I'm forgetting one.) Likewise, I have a perception that we tend to be awarded a lot more free kicks later in the match when the contest has effectively been decided than in earlier parts of the game when the result is in doubt. I think it was Brentford at home for instance when the opposition didn't - according to the referee - commit a single foul in the first hour of the game and then committed about 10 in the next 30 mins. Whether there is anything in that, I don't know, perhaps it just feels like that.
It wasn't, by the way, a pain to put together. There had been some perception that we get less time added on but no real evidence of it. I shared that perception but wasn't really able to say whether it was based on anything more than gut instinct. So putting the data together, which took about half an hour, was a way of satisfying my own curiosity as much as anything.
And, as I say, the numbers don't lie. We can all interpret the data according to our own opinions, and I don't challenge anyone's right to come to their own conclusions. What I do say is that the feeling some had that we were being short-changed in this respect is backed up by the numbers.