The correct answer is the ‘right curly quote’ (as in ’14)—no question about it. As others have pointed out, it’s actually an apostrophe (showing the omission of one or more digits), and apostrophes always point the same way as right quotes.

The only reason you’ll see it pointing the wrong way is computer software. Some software automatically turns straight quotes into curly ones by looking at the previous character: if there’s a space before it, it will decide that it’s a quote, not an apostrophe. Now this works a lot of the time, but it fails when the apostrophe is at the beginning of a word (such as in ’tis)—or, in this case, dates.