Planetary Function

In the table each row corresponds to one of the eight planets orbiting the sun, listing the length of its year and how far from the sun it is on average. Notice that the earth has a year of length 1 and a distance from the sun as 1. In other words, the other planets' year and distance are measured in terms of the earth's.

Length of Year Versus Distance from Sun

Is there a relationship between how far a planet is from the sun and how long it takes to go around the sun? If there is, can it be expressed quantitatively? The plot of distance versus year certainly suggests that there is a quantitative relationship. Your goal is to find the formula that fits the points.