Selected answers from the Dumb SEO Questions Facebook & G+ community.
Karol Soja: Do you know any way to check historical data for keywords search volume? 4 years back.
Suraj Gadage: +Karol Soja ;It's difficult to get historical search volume of a keyword. You might want to use Google trends to measure increasing or decreasing interest over the time or to pinpoint high points in seasonal searches.
Or if you are open for trying paid tools then check Semrush for historical data.
FYI: Historical data are available on Guru and Business plans only.
Hope this helps!
Karol Soja: +Suraj Gadage Oh Thanks :) I have Semrush Guru and you are right - I can check there this historical data. Unfortunatelly there are no data for my country(Poland), but data for US will be also helpful.