Explanation:
Pick two columns from the table to form the (x,y) points.
I'll pick the last two columns, since everything is positive here. So we have the points (2, 17) and (4, 45)
Apply the slope formula to those points
m = (y2 - y1)/(x2 - x1)
m = (45 - 17)/(4 - 2)
m = (28)/(2)
m = 14
The rate of change is 14.