I have a table of clients with their birth year:

* Koen Peeters, 1987
* Sara Stas, 1989
* Karel Tosijn, 1986
* Koen Peeters, 1988
* Koen Peeters, 1950

I want to create a new table grouping the clients by name, and by year. 

But the problem is that there is a -1,+1 error margin on the year of birth. So Koen Peeters born in 1987 is the same as Koen Peeters in 1988, but the Koen Peeters born in 1950 is a different Koen Peeters.

Is it possible to do this in SQL? It is kind of a fuzzy group by?