human
stock performance graph: the graph below shows the cumulative total shareholder return assuming the investment of $100, on december 31, 2013, and the reinvestment of dividends thereafter, if any, in the company 2019s common stock versus the standard and poor 2019s s&p 500 retail index (201cs&p 500 retail index 201d) and the standard and poor 2019s s&p 500 index (201cs&p 500 201d). .
|  | December 31, |
| Company/Index | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 |
| O’Reilly Automotive, Inc. | $100 | $150 | $197 | $216 | $187 | $268 |
| S&P 500 Retail Index | 100 | 110 | 137 | 143 | 184 | 208 |
| S&P 500 | $100 | $111 | $111 | $121 | $145 | $136 |
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Please answer the following questions with expressions if necessary.
what is the net increase in a $100 investment in o 2019reilly automotive inc. from 2013 to 2017?
assistant
subtract(187, 100)
human
what is the initial investment?
assistant
100
human
what roi does this represent?
assistant
subtract(187, 100), divide(#0, 100)