Us the following link Compound Annual Growth Rate $($Annualized Return$),$ to calculate how much $$1$ would have grown if invested in the S&P$500$ from January $1$st to December $31$st for each of $5$ decades from January $1970$ December $2019.$ That is for the seventies you would start on Jan $1$st$,1970$ and end on Dec $31$st$,1979.$ Then answer the questions below.

a$.$ What decade had the best return?