code: def display_monthly_returns(self):
          
          data = [['Year', 'Jan', 'Feb', 'Mar', 'Apr', 'May',
                   'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec', 'YTD']]
          for k in self.return_table.index:
              r = self.return_table.loc[k].values
              data.append([k] + [fmtpn(x) for x in r])
          print(tabulate(data, headers='firstrow'))
docs: Display a table containing monthly returns and ytd returns
          for every year in range.