Interest On Pf - Xls Download

Hi All,
Can any help me how to calculate Interest on PF accumulated:
These are the amounts deducted from my salary from Oct-07 to Apr-10.
Oct-07 265
Nov-07 418
Dec-07 432
Jan-08 432
Feb-08 432
Mar-08 432
Apr-08 374
May-08 334
Jun-08 432
Jul-08 432
Aug-08 432
Sep-08 432
Oct-08 747
Nov-08 485
Dec-08 485
Jan-09 485
Feb-09 457
Mar-09 485
Apr-09 396
May-09 487
Jun-09 487
Jul-09 490
Aug-09 487
Sep-09 480
Oct-09 419
Nov-09 487
Dec-09 485
Jan-10 438
Feb-10 478
Mar-10 387
Apr-10 274
Total 13785