It seems a lot (200) when written down but it’s over a 3 month trial, let’s do the maths for completion !
All fair let’s say 17 questions each over 3 months, only 5.6 questions per month per juror, a little over 1 per average week. Let’s not get bogged down with the questions.
Just because this particular journalist has reported this figure doesn’t mean it’s not happened before on a long running trial, it’s just not been reported.
There is unlikely to be a reporting bias, given that there are reports of tens of thousands of trials on the record, and not a single one AFAIAA has ever mentioned there being more than 10 jury questions.
Let's do the maths indeed. Your denominator is a poor choice. The questions have been put to witnesses. The denominator should be the combined length of time for which witnesses have been in the box. My guess of 20 minutes implies 20 minutes * 200 = 4000 minutes ≃ 67 hours, which sounds reasonable. If it was 100 hours of testimony that would be 50% more, giving one question every 30 minutes rather than 20 minutes.
For a benchmark: 10 weeks each of 4 days, each with 4 hours of witness evidence would be 160 hours of witness evidence (giving 1 question per 48 minutes). The real figure for combined witness time during this trial was surely much lower than 160 hours. Someone can go through the reports, but I doubt it went past 100 hours.
As for questions per juror, yes that's a statistic, but I can't see that it's relevant given that there are always roughly the same number of jurors, and given further that the distribution of questions is extremely unlikely to be anything close to flat.
Very probably more than one juror asked questions, but my working hypothesis is that one of them is the instigator (this is extremely rare behaviour) who may have set one or more others off, probably at a slower rate (that's what sounds social-psychologically likely).
I trust we can all share the hope that question asking has not messed up the working of the wheels of justice in this case, and that no juror is unduly influenced by what they may feel is irritating, time-wasting, or narcissistic behaviour by any other juror who, they may feel, has an unusual set of beliefs or personality.