I certainly see what you mean ... but what I don't understand is why parents in the 1980s (not the 1890s!) suddenly started making a statistically significant number of errors with their
Elizabeth,
Melissa and
Sarah daughters. Had the forms changed and become confusing? Otherwise surely the 70s parents would have been doing the same kind of thing, and the 90s ones?
Anyway, what you didn't say is probably as important as what you did: you haven't had direct personal experience of any boy named
Lizzie, right? (And if right, then PHEW!)