Suggestion You can easily make one yourself. Google “clock face clip art” and among the various image returns (usually will be one of the first ones) will be a white clock face with only the hour numbers showing. You can paste that into a text editor or drawing app, resize as desired, and put in the percentage numbers yourself.
02:30 35% (or 38% I have seen both)
Just continue around the clock face with the same percentages at the appropriate hour markings. It will look almost exactly like the one you remember (which you probably saw in a YouTube video about wind aiming). You’ll find though after using this for a period of time you will have memorized the percentages and their relative positions and will no longer need to rely on the image.