How to do Group In Datatable

HI
I have a datatable like follows
Year     Amunt1    Amount2
1998      100       0
1998      200     0
1999      300      0
1999      400       0
2000       0    400
2000       0       200
2001      100    200
2001      200    300
2002    0       200
2002    0       300   
I want the result of the above datatable like below
...