If you go out there and look at the threads on individual programs , some of the residents get on there and throw some numbers out in regards to how many they are placing. I would have to say it varies but I'm not sure depending on the program.
You're probably not likely to get a real answer here. These numbers are actually hard to come by, even during the interviews. There are certainly programs that do more implants than others but you can be assured that comes at the expense of other surgical experience. Personally, I'd focus on avoiding the programs whose resident years consist almost entirely of implants and dentoalveolar and those that do essentially zero. The former are more common than the latter based on my experience.