Google Webmaster Tools is one of the last places, where it is possible to learn information about keywords from Google organic search.
Even in Webmaster Tools, you may see only a smaller slice of data:
And this slice is even smaller, when you realize that it shows you data from only last 90 days. You may see data in Google Analytics, if you have connected these two services, however, the Webmaster tools data are usually more accurate.
Therefore, it might be a good idea to backup these data in order to use them in latter analysis with Excel or other tools.