Neither of us have accurate figures. Do I need a stat to back up an opinion I have based on watching football on a regular basis? Of course not.
I wasn't talking about this tournament or even the past season, I was talking about their careers. I agree that it's debatable for Agüero, I have no problem admitting that (though you might point towards his league winning goal as stepping up in a big game, that comes to mind quickly, and maybe some big performances for Atletico ? But I don't know that), the others I can point to multiple big games where they've stepped up throughout their careers. I don't think Özil has ever been that type of player though, yep there will be some isolated cases where he turned in a good performance in a big game, but I'm just pointing out that for me, him disappearing when the stakes are high or the pressure is on his team is a trait of his game.
I have no problem with you disagreeing though, if you feel he's a big game player or if you think the ones you've listed aren't or never have been. And I won't point towards stats to prove my opinion is right over yours. It's just your informed opinion.