You may be able to use the method suggested by Mukram is a slightly different way to get your result.
You could try creating a key and then using the group by function in order to get the FirstTO_Year.
Essentially just add:
Field1+Field2+Field3+Field4...... as KEY
then just create a new table
Min(Year Field) as FirstTO_Year,
Group By KEY;
This will then give you the first TO year for each key, so basically you just need to create a key from all the fields you want to differentiate the turnover by. Sorry if this isn't what you are after, I can't open any QVWs for today.