There is a small amount of officially-released statistical data in English here.
The "History of Comic Market" section of the "What is Comic Market" PDF shows a chronology chart of the number of participating circles (32 in the first Comiket, up to 550,000 in a recent Comiket), and the following pages of the PDF list more specifics.
In terms of volumes of doujinshi sold and the types of them, I do not beleive that the specific info you seek has been collected. Comiket is massive and when I sold doujinshi there last year, all of the booths in my area just started closing up shop near the end of the day, without (as far as I know) being required to keep track of how many volumes we sold nor needing to report that number to the organizers of Comiket.
The best way to attempt to measure which series are represented would be to get ahold of the massive phonebook-sized program booklet from each year and count the number of circles that used a particular series as its sole illustration in the book to advertise its work. For example, how many picked to use Cardcaptor Sakura, how many picked to draw Evangelion, etc. However, this would only give you a general sense, since of course one circle might draw doujinshi for more than one series, and might even not choose as its one illustration entry in the guidebook whichever series that it sells the most volumes of.
From what I saw when I was there, and from looking through the program book of that year, Nanoha, PreCure, and Gundam were not big representations (Nanoha and PreCure are not long-running, anyway, as far as Comiket is concerned - they're pretty new series when you consider everything that's been produced since 1975). The ones I saw represented a lot were more old-school ones like Evangelion and series from that era; this also makes sense since the original otaku of such series would largely be in their 30s and 40s, even early 50s now. It should be noted that about 90% of the doujinshi I saw for sale was all hentai (not the tasteful, romantic sort, but the explicit sort), so the target demographic would reasonably have some bearing on which types of series are represented (i.e., what kind of series do the people who like hardcore hentai tend to like?). Comiket would not attract many of your average Japanese anime-watching demographics for that reason (I ended up not finding anything to buy). People who like sweet fluff or sci-fi action stories or any number of interesting genres that the realm of anime offers us would not necessarily be interested in the very specific subset of doujinshi that you can find at Comiket. Of newer series, Madoka Magica had some representation.
