I have had a Campbell Stokes Type Sunshine Recorder since the end of April 2022. It is a beautiful instrument. I have to change the card after sunset each day. The results are shown in my Manual Records here.
The photo on the right shows the sky inverted in the glass sphere of the recorder. Nice!
For full details of the recorder and the Sunshine Record Cards are on PDFs by year updated from time to time.
As can be seen the holes in the 2023 cards are much bigger. This got me thinking.... The Sunshine Hours will appear top be more with the newer cards. So, using Matplotlib and Python, a couple of Scatter Plots and some Linear Regression later we finish with these plots.