I want to create a shake effect to a video clip while making it zoom. I tried doing it using the pan/crop tool. I first created the shake effect using the pan/crop feature of the clip on the timeline. I did that by creating four keyframes after each frame with different x and y values.I then did a copy/paste for the four keyframes for the entire clip. However, after doing this I couldn't find a way to create another keyframe for the zoom-in because a single keyframe at the end of the clip won't add it's effect on the previous keyframes for the shake effect.

Therefore, I  would like to know how do I add both the zoom-in and shake effects using the pan/crop tool using the keyframes at the same time?