In the survey results, the values displayed in the answer table are ranges to determine the confidence interval. This is to say that if you were to run the same survey again, there's a 95% chance that the percentage of respondents who chose that answer would be in that confidence interval range.
In the following example, the confidence interval indicates that there's a 95% chance that the percentage of respondents who chose Answer A would be between 43.4% and 24.8% if you run the survey again:
Answer A 33.5% (+9.9/-8.7)
This calculation is based on 33.5 + 9.9 = 43.4 and 33.5 - 8.7 = 24.8.