This is an Interim Trend Volatility of Retained Earnings over 5 years. Trend Volatility is derived by subtract the log linear Estimated index value (in index value units) from the Actual index value and divide by the Estimated index value to derive a % deviation. Repeat this for each observation and average the .absolute. results to derive a % Mean Absolute Deviation. Express this result as a percentage. Required 11 latest semi-annual or 21 latest quarterly periods. Retained Earnings represents Income Available To Common Excl. Extra Items minus Gross Dividends - Common Stock for the same period.