Well about 15+ ideas. I'm just working on anthologies and a webcomic that i run on side, but with time i hope i can move on to my main ideas and for now it's just a hobby. To be honest all the scripts i write end up being created (drawn).
Just had my first publish in england, still got 2 more publishes lined up already in the next 4 months. (all pages are already drawn). While the publishes are nice and awesome all of current comics i did were 5 pages and less. Moving on a 10+ script soon, it has been gathering dust for almost 6 months now.
So the answer would be kinda:
Short stories: Depends on anthology type with an open call
One shot with 30 pages or lower: About 4 or so currently
Smaller series: 4 ideas
Ep: One idea (magnum opus)
So far: Finished 4 short stories and running a webcomic to fill the time in between.
All you need is patience.