Using one or more online sources, determine the annualized total return (i.e., including dividends reinvested), volatility (using monthly returns), and Sharpe ratio of Berkshire Hathaways Class A shares (ticker symbol BRK-A) for the five years ending December 31, 2020 (i.e., 2016 - 2020 inclusive)? [Note: you may assume an average annual yield of .50% for U.S. T-Bills.]