At least I wrote: “I believe” re the number 7.
Your 10-12 per century was pretty far off.
NASA lists the statistics on line
Last 15 centuries ranges from 0-8max occurrences tetrad per century. Average 3 per century. your figure was about 4x exaggerated.
My figure was about 7x enaggerated.
So you would win except you didn’t write: “I believe”