As of 2 years ago, there were 35117 ai/uca/ucb/ucs files. 7334 of that are angled animations. 10821 of that were scenery other than angled animations. 6572 were foliage. 4376 were animals. 1464 were guest buildings. 1454 were rocks. 1270 were paths. 1109 were fences and walls. 450 were shelters. Other categories are less. Of course there are many GBs of unique zip files.
Also there are limits on how many ztds can go in the game before it crashes.
There are still a lot of problem files around, although not so many here at Tek.