This question is not Russian language-related strictly speaking, but I think it's useful for a lot of people using the language. I wonder if it is possible to use the ruscorpora.ru website to build the comparative word usage frequency distribution by year for two (or more) words. I have found the user manual, but couldn't find the answer there.
For example, I'd like to compare the words скакалка and прыгалки, i.e. have these two plots — first and second — plotted in the common axes.