Linear Fit

This looks basically linear, so let's define our linear least-square fit using the Mathematica Fit function.  We tell it to fit this data to the functions 1 and t (a constant and t to the first power):

Let's graph this and see what it looks like (I use the same PlotRange as before, but make it blue):

And now, display them together:

This doesn't look like too bad a fit.