Mine ended up being around 25 to 30 miles when I wasn't thinking about training for anything. I lost a lot of mile by not running on the weekends. I would be traveling or hanging out with people and wouldn't make it a priority.
After my next marathon i think im just going to go back to that for a while. just maintenance miles as i call them.
i guess in my case i am still always planning on being competitive again. i guess its more just a down period.