>You can try correlatade subquery but it most likely will be much slower
>

>Select * ;
>	from PrevYear ;
>	WHERE NOT EXISTS ( SELECT * FROM thisyear ;
>				WHERE PrevYear.mijbrpls = thisyear.mijbrpls ;
>					and PrevYear.vlgnr_mut = thisyear.vlgnr_mut )
>

>

This is indeed much much slower. I have found a solution with Edward's help. As always, thanks for your help.