Researchers in Finance find that, in general, stock market performs the best in January, and the worst in fall, such as October. You would like to test whether this is accurate.

You will do so by calculating the historical monthly holding period returns of S&P 500 index from 1950 to 2019. Across these 80 years of monthly data, you will calculate the average returns for all 12 months (Jan, Feb, Dec) and find out which month performed the best and which month performed the worst.

There are multiple ways to do this, some ways are smart, only take a couple of minutes, some ways are more time-consuming and tedious. You are free to use any way you can think of.