ubiquitin: Correct but Assoro b’Teves on Thursday is only very fractionally rarer than on Friday, maybe 2 times or so less frequent than on a Friday per century.
Of the 14 Jewsih calendar Keviusim:- 4 of them result in Assoro b’Teves on Sunday, Tuesday & Friday respectively, but only 1 Kevius results in Assoro b’Teves on Thursday & Wednesday respectively. But the 1 Kevius resulting with Assoro b’Teves on Thursday, is by far the most frequent of the 14 Keviusim on the Jewish calendar:- “HKZ” Rosh haShono on Thursday followed by Kesidron followed by Pesach on Shabbos.
Daas Yochid:- I second thy motion.