what was the percentage cumulative total shareholder return on discb common stock from september 18 , 2008 to december 31 , 2008?
2 0 0 8 a n n u a l r e p o r t stock performance graph the following graph sets forth the performance of our series a common , series b common stock , and series c common stock for the period september 18 , 2008 through december 31 , 2008 as compared with the performance of the standard and poor 2019s 500 index and a peer group index which consists of the walt disney company , time warner inc. , cbs corporation class b common stock , viacom , inc . class b common stock , news corporation class a common stock , and scripps network interactive , inc . the graph assumes $ 100 originally invested on september 18 , 2006 and that all subsequent dividends were reinvested in additional shares . september 18 , september 30 , december 31 , 2008 2008 2008 .

|  | September 18,   2008 | September 30,   2008 | December 31,   2008 |
| :--- | :--- | :--- | :--- |
| DISCA | $100.00 | $103.19 | $102.53 |
| DISCB | $100.00 | $105.54 | $78.53 |
| DISCK | $100.00 | $88.50 | $83.69 |
| S&P 500 | $100.00 | $96.54 | $74.86 |
| Peer Group | $100.00 | $92.67 | $68.79 |

s&p 500 peer group .

discb_final_value = 78.53
discb_initial_value = 100
percent_return = (discb_final_value - discb_initial_value) / discb_initial_value
answer = percent_return * 100