We have the general social survey of 2002, which asked the question, “Why did you come back?”, and 22% of those who retired the first time did come back. It was in 2002 and the question was not asked again.
The reason people said they came back was because they didn't like retirement. They liked working and they wanted to give something back to society. For some of them, it was for financial reasons.
We can provide the tables if you want.