Wouldn't we expect the mode to be 75, while the median and mean would be younger? Assuming, of course, that Wizard of Oz produced any sort of lasting increase on the popularity of Dorothy as a name.
I wouldn't expect a lasting increase more of a S curve. Movie comes out, there is a spike in Dorothy usage. A few years pass and the original spike slows down. Then the movie is seen as old fashioned and you start to see a negative trend. Then Dorothy is seen as an old lady's name so it sees an even sharper decline.
True, and with the population growing generally we'd see it pushed back toward that spike...
The median is actually not 75 exactly, I looks to be 74ish on the graph. This makes sense.