Using the WDI package in R, look for the following term: stock market return. It is associated with variable name: GFDD.OM.02. Use R to find the median stock market return for the United States from 1984 to 2017. Then, fill out the blank. The median stock market return for the US from 1984 to 2017 is about _____ percent. (Enter your answer with two decimal points)