I need to get:
2 30 25 01/02/01
4 50 26 01/02/02
6 100 27 03/01/03
The rules how this subset is chosen are :
I need to return ID for Maximum amounts in each group.
If there are 2 or more records with same max amount and group - then pick with older Maturity Date.
If there are two or more records with same max Amount, group AND Maturity Date - then pick max ID.