How many survivors died on the anniversary of the sinking?

I have have noticed that several survivors later died on the anniversary of the sinking. (The only one I can recall offhand is Selma Asplund, the mother of one of the three living survivors and the only one in the US, who died on the 51st anniversary.) The phenomenon of people delaying death temporarily in order to reach a significant anniversary or date is fairly well established. This happened around Jan. 1, 2000, for example. It might have happened to the Titanic survivors, too. Has anyone enumerated how many survivors died on April 14 or 15 in later years, or if not is there any easy way of generating that information?
how do you delay dying for another day or week, maximum?