depends what you mean by "all of these".
If you just want the slopes of the 6 consecutive line segments, it wouldn't be so bad
take slope between (0.0) and (20,.166)
then the slope between (20,.166) and (40,.181)
add up the 6 slopes, then divide by 6
If you really want "all of them",
that would mean the slope of
first point with the second, with the third, et
then the second point with the third, with the fourth, etc
there would be 21 such line segments.
Good luck, and lots of patience.
Obviously I am not going to do this for you, I just told you HOW to do it.