Here are the SARSAT rescue statistics: NOAA - Search and Rescue Satellite Aided Tracking - Statistics
If you read these forums, you will discover there is a wide divergence in opinion on this subject. I believe common sense and problem solving play a large role in these incidents, much more than the boat or gear or training. Many seem to think if they only have the right boat, the gear, the right set up, the right training, they can ensure safety when they set off to sea. If you read these forums, you will discover incidents with all these factors, yet a lack of common sense and good judgment results in a disaster.
Why are you interested in this subject?