what is the roi of an investment in state street corporation from 2007 to 2009?
shareholder return performance presentation the graph presented below compares the cumulative total shareholder return on state street's common stock to the cumulative total return of the s&p 500 index and the s&p financial index over a five-year period . the cumulative total shareholder return assumes the investment of $ 100 in state street common stock and in each index on december 31 , 2007 at the closing price on the last trading day of 2007 , and also assumes reinvestment of common stock dividends . the s&p financial index is a publicly available measure of 80 of the standard & poor's 500 companies , representing 26 diversified financial services companies , 22 insurance companies , 17 real estate companies and 15 banking companies . comparison of five-year cumulative total shareholder return .

|  | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| State Street Corporation | $100 | $49 | $55 | $58 | $52 | $61 |
| S&P 500 Index | 100 | 63 | 80 | 92 | 94 | 109 |
| S&P Financial Index | 100 | 45 | 52 | 59 | 49 | 63 |

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initial_investment = 100
final_investment = 55
answer = (final_investment - initial_investment) / initial_investment * 100