I recently posted on the Knights QRSS forum (https://groups.io/g/qrssknights) a look at how the 28MHz WSPR data compared to the observed results amongst the QRSS mode users on the same band. The results tied in with the WSPR data. If you have a look at my QRSS Gallery page you will see some interesting 28Mhz grabs,especially the ones showing solar flares. I'm hoping that the data might give us a clue as to how the 28Mhz band reacts throughout the next sunspot cycle, and that us QRSS users can prepare ourselves. The same for WSPR users. Also just for fun I looked at the WSPR data for the other end of the spectrum, 160m to see how things reacted. The chart clearly shows the seasonal changes.
Of course bear in mind that when WSPR first started, there were not many reporters. So it really comes down to observing the peaks and the troughs, and not actual numbers in these two cases. The data represents almost a complete solar cycle. Not perfect but useful..The data in .csv format is available for anyone wishing to play around with the data, and can be downloaded on the link at the bottom of the page.