The Survey Metrics View will let you know all the stats about the surveys you sent out. Use the date-picker in the upper right of the view to see stats for specific time-frames.
Survey Counts
Delivered - How many surveys were successfully delivered
Scheduled - Amount of surveys total you have scheduled in the future
Bounced - Amount of surveys that Bounced/Dropped
Unsubscribed - How many surveys were unsubscribed from
Response Rate
This will be the percentage of how many contacts responded to surveys that were successfully delivered. (feedback count / delivered count)
Comment Rate
See what percentage of contacts that responded left a comment.
(# of feedback with comments / total number of feedback)