Logic Pro X Slow Drum Tempo Down At Last Measure

Hi,

I have a simple recording in Logic. The recording is a guitar - the guitar slows down at the last measure. I need a simple way of slowing the drummer. I have Global Tracks visible and in the Tempo region I can manipulate (change) the tempo at any point in the song. However, I haven't figured out how to linearly decrease the tempo - I can only change tempo in discrete steps. The annotated screen capture illustrates what I'd like to do.

Is this possible?

Side note: I did try using the follow check box with the drummer - but the drummer didn't follow the guitar getting slower. =/ So, I just figured I'd slow the tempo manually being that it's just at the end.