You can manually grade all sizes simultaneously, by a fixed amount, using the Increment tool.
To use the Increment tool:
If it is not already open, open the Sizes and Grading pane.
In Set Increment, type in the value you want for the increment.
In the 2D window, select one or more grading points.
Click the appropriate arrow to adjust the grade points as required:
Note
In all cases, the base size grade point does not move.
The Incremental and Relative to Base data in the Sizes and Grading pane is automatically updated.