How to adjust serial numbers in a grid edit report while inserting the rows in between

Hi ,

The requirement we have here is 

Serial number field is Numeric data type. We have to adjust the serial number column in the grid edit while inserting any rows in between the existing rows. I have tried multiple ways but that is not working as we expected.

Example: Suppose If we have 10 rows with serial number 1,2,3 ---10. And user insert the two rows in between 2 and 3 , then the expected result is 1,2,3,---12. But we are getting result is

1,2,3,4,3,4,5,6,7,8,9,10.

Kindly suggest us if we have any solution.

Thanks & Regards,

Madhavi.