Line Plots · Medium problem

A line plot shows how far some snails crawled, in inches. Above $\dfrac{1}{8}$ there is $1$ X, above $\dfrac{2}{8}$ there are $3$ X's, above $\dfrac{5}{8}$ there are $2$ X's, and above $\dfrac{7}{8}$ there are $2$ X's. How much farther did the snail that crawled the farthest go than the snail that crawled the shortest distance? Give your answer in simplest form.