I was wrong. It was eleven years.
I was tricked by this photo of 70s supermodel and 19th-century dirigible villainess Apollonia van Ravenstein.
But the caption from the 1979 issue set me straight:
Sashaying on Praslin’s Côte d’Or, Apples reveals another side of her fishnet suit. The end.
The word “another” implies that there was an earlier photo at her fishnet suit, and sure enough, this is the same swimsuit:
…and she isn’t topless at all.
That sends us forward to Kim Alexis in 1982, with this shot.
Again, the caption feels the need to call it out, referring to the suit (somewhat strangely) as “one-piece topless.”
With this, we are off to the races. Nearly every swimsuit issue after this one features at least one topless suit.