Weird Coincidence

Tonight at supper a friend was discussing how busy this month has been and mentioned December birthdays of her kids and grandkids and then mentioned in passing that the 26th was her father's birthday. I said "Really? That was my late father's birthday as well." Then my brother-in-law piped up that the 26th was his father's birthday also. So, out of five people at the table, three (or 60%) had fathers born on 26 December. None were born in the same year (1918, 1926 and 1927). What are the odds?