I am working with the time series of solar activity 1850-2023 with the average monthly values of the number of sunspots.
I have a question that I tried to find an answer to, but due to the lack of some base, I could not finally answer my question. What frequency should be specified in this case for ts()? After all, a number of solar activity is characterized by an 11-year cycle. Is the frequency = 12*11 then? Or is it enough to leave the frequency equal to 12?The question seems to be simple, but it causes some uncertainty, please help