If you’re talking about baseball, batting .500 would be an impressive feat. But when you’re talking about getting 50% of punctuation right, you’re not doing great. And you probably are looking at the Yahoo! front page.
A compound modifier consisting of a number and a unit of measurement (that’s not abbreviated and precedes the noun it modifies) requires two hyphens. So there’s one hyphen missing here:
and another here:
Maybe we should just congratulate the writers for getting one hyphen right!