Pan speed not constant in animated image
I want a pan to have a constant rate of speed between the 2 sets of keyframes in my animated image. I Googled it and found instructions to select the 2 sets of keyframes by dragging a selection box around them, then right-click on one of the keyframes and select Linear in the Temporal Interpolation option. Its still slowing down towards the end, much faster at the beginning. I've attached a screen shot but I don't know if it shows anything helpful. Any help would be appreciated. Thank you.

