Please help me answer this question, I do need to be walked through how you arrived at the answer.

Use the data below to solve for the sustainable growth rates for 2011 to 2015. Profit Margin Retention Ratio Asset Turnover Financial Leverage Sustainable Growth Rate Actual Growth Rate 2011 17 1 0.38 1.64 2012 17 1 0.49 1.44 2013 79.3 1 0.55 1.79 2014 22.8 1 0.63 1.99 2015 23.6 1 0.62 2 26.1 40.1 43.5 40 26.3 What is the sustainable growth rate for each year? Based on your analysis of the sustainable growth rate between 2011 and 2015, what are your recommendations for the firm