Excel spreadsheet

I need formula to calculate

Monthly return s&p 500

And monthly return google

Bonus Problem - Read-Only - Compatibility Mode Exce Insert Page Layout Formulas Data Review View Tell me what you want to do General Conditional For FormattingTa Style Paste B 1-6- Format Painter Clipboard Font Alignment Number SUM 1 Date Adj Close S&P 500 Index Adj Close GOOGL Stock Price Monthly Return S&P 500 Monthly Return GOOGL 21 3/1/2012 3 4/2/2012 320.94 02.73 290.72 290.33 1408.47 1397.91 4 5/1/2012 5 6/1/2012 1362.16 1406.58 1440.67 1412.16 1416.18 1426.19 1498.11 1514.68 342.89 377.63 340.49 49.53 354.04 8 9/4/2012 9 10/1/2012 10 11/1/2012 11 12/3/2012 12 1/2/2013 13 2/1/2013 14 3/1/2013 97.49 15 4/1/2013 1597.57 630.74 1606.28 16 5/1/2013 76/3/2013 18 7/1/2013 19 8/1/2013 20 9/3/2013 21 10/1/2013 22 11/1/2013 3 12/2/2013 436.05 440.63 1632.97 1805.81 1848 36 530.33 560.92 table-1