limited number of jedi

anyone have theories on why aotc begins by stating that there are only a limited number of jedi? i mean why are there a limited number to begin with? is this just a statement of fact, or has something reduced the number of jedi? is the dark side gaining so much strength that palpatine is hiding more potential padawans beneath a veil, so that the jedi have a difficult time locating them? i ask this because it is obviously very important to the plot line.
and on a side note many jedi are killed in aotc,(many in lame situations, i might add) leaving even fewer behind. this obviously is key to ep III.

 

I know it's not answered anywhere in the film.

As for the Expanded Universe, it tends to alternate between saying that the ability to use the Force is rare and that there are lots of folks who can do it.

In my viewing of the films, I'm getting the impression that the ability to use the Force to the extent that you can dedicate your life to it is pretty rare. I think one of the reference books for Episode II indicates that there are about 1,500 Jedi around the galaxy? Not very many.

So there's absolutely no answer to your question.