script count?

hi all,

does anyone have a count (and a reference for it if possible) for

1. how many scripts are in use today (living languages) in the world?
2. how many are known (living and dead) in the world/throughout history?
3. how many are used in africa (either way)?

I know i've seen this info somewhere, but cant seem to find it. It
occurred to me to go through 'the worlds writing systems' and count,
but that seemed a little overwhelming.

:)

thanks
gabriella

ps. by script i mean to include scripts, syllabaries, alphabets, and
anything else that might be construed as a writing system.