Looking for Google specifics for thesis...

Working on a thesis for MAIB, need both general input from everyone and more specific input if anyone is in the know:

For anybody:

(1) Your experience of the AdSense failure rate, when the AdSense code displays public service announcements instead of relevant advertisments; for example, when I am checking my sites I see AdSense display PSAs about 1 out of every 20 pageloads.

More specific: (If you could provide citations I'd be ever grateful.)

(1) Estimate of webPAGES running any form of the AdSense code;

(2) Estimate of webSITES running any form of the AdSense code;

(3) Number of AdSense advertisements served daily;

(4) Estimate of total AdSense advertisements for the year.

Obviously the last four will have to be found by someone close to Google or from Google documents themselves. I didn't know if Google was sending out estimates of this nature, but it would be nice to have for my paper if anyone knows!

Thanks!

Take care,

... Christopher