“We've been accused of making the same album over and over 12 times,” guitarist Angus Young once said. “The truth is, we've made the same album over and over 15 times.”
To paraphrase Angus Young: "I'm tired of people saying that we put out 11 albums that are exactly the same. We've put out 12 albums that are exactly the same."
Although I think that was a while. I think they've released a few more versions of their first album since then.