Official website page: Successful Second Deep Space Maneuver for OSIRIS-REx Confirmed

The graph shows the spacecraft speed wrt the Sun during the DSM-2 and the resulting acceleration.
The change in the velocity vector was 16.9 m/s, while the change in the magnitude of the heliocentric velocity was 2.54 m/s.

Official website page: NASA's OSIRIS-REx Executes First Asteroid Approach Maneuver

Change in the velocity vector: 351.251 m/s
Change relative to Bennu: from 491.264 m/s to 139.995 m/s (351.269 m/s).

Official website page: NASA's OSIRIS-REx Executes Second Asteroid Approach Maneuver

Change in the velocity vector: 137.066 m/s
Change relative to Bennu: from 140.956 m/s to 5.308 m/s (135.648 m/s)

Official website page: NASA's OSIRIS-REx Executes Third Asteroid Approach Maneuver

This two-step maneuver changed the speed relative to Bennu from 5.230 m/s to 2.700 m/s and to 0.870 m/s

Official website page: NASA'S OSIRIS-REx Spacecraft Arrives at Asteroid Bennu

The graph shows all the maneuvers starting from AAM-1 (notice the logarithmic vertical scales).