I only have my own personal anecdote, but I was the top boy in my highschool class by far. That didn't even get me into the top 10% of my class, though, since the top 10% were all girls. I think the only other boy in the honor society was a boy from the next year's class but I can't remember. (I know who the next highest boy in the school's ranking was but I don't remember whether or not he hit the cutoff for honor society.)
This was during the 90s in a public high school, so it wasn't like the population was simply unbalanced. This is hardly a new problem. Our education system simply doesn't engage with boys and hasn't for years at this point.
If you want links, though, it isn't hard to find them:
Itâ(TM)s Time to Worry: Boys Are Rapidly Falling Behind Girls in School
How to Make School Better for Boys: Start by acknowledging that boys are languishing while girls are succeeding.
Education: Boys Falling Behind Girls in Many Areas (Paywalled, so I have no idea what it says)
Those were just the top results on Google.