[Closed] How to get values between keypoints in animations

I need to build arrays of values for camera animations. We have animated FOV, so there are a bunch of keyframes.
Now, can you get the values between the keyframes?
For example
key1. (time 0) FOV=10
key2. (time 100) FOV=100

I want to get the value at time 50. I expect the FOV to be about 55 in this case. Can I do that?

Thanks
/Andreas