I am monitoring the number of pages indexed by Googlebot for one of my websites .
I noticed that since last week, the number of pages has dropped by about 60 or so. Now to be fair, I have not added that much over the last week. (Actually I don't think I added any new content.) But at the very least, I would have thought that the number of indexed pages would be static (if I was not adding anything new.) I don't understand why the numbers have dropped.
Does anyone have an official explanation for this?. I have checked the Google Webmaster Tools, and have not come across anything that addresses this issue directly.