First I was going to ask how many rocket bodies lay at the bottom of the ocean, but I simplified further.
Remember, this includes sounding rockets; anything passing the Kármán line.
I'm looking for a good guesstimate. I'm sure it's more than a thousand and less than a million, and guessing that it's probably about half-way between on a log scale (~31,600).
Food for thought; Gunter's Space Page has a map of launch sites worldwide http://space.skyrocket.de/directories/launchsites.htm Here's a screenshot at maximum zoom-out: