When did Emerson start the double detents?

[CL01]

I just got an Emerson CQC7A (A '10) & was comparing it to my old '99 CQC7B. Other than the blade shapes, I noticed the double detent right away. I can understand the why, but when did Emerson do this?

I've had some other models in the past, but don't recall seeing that, although they were a few yrs ago (Probably '08 or earlier).