The fact that Newt’s lifetime ACU rating was 90 is evidence that his voting record over his two decades in Congress was overwhelmingly conservative. But the fact that Newt had a 100 ACU rating in 1998 tells us next to nothing, since Newt was Speaker that year and the Speaker very rarely votes unless there’s a tie. I wouldn’t be surprised if the only 1998 votes scored by the ACU in which Newt participated were regarding the Clinton impeachment.
You are right, but he did vote in 12 of the 25 votes scored.