Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
The Proletariate and the Equestrian Order under the Restoration
While the restored government was thus careful thoroughly to eradicate
the germs of improvement which existed in the Gracchan constitution,
it remained completely powerless in presence of the hostile powers
that had been, not for the general weal, aroused by Gracchus.
The proletariate of the capital continued to have a recognized title
to aliment; the senate likewise acquiesced in the taking of the jurymen
from the mercantile order, repugnant though this yoke was to the
better and prouder portion of the aristocracy. The fetters which
the aristocracy wore did not beseem its dignity; but we do not find
that it seriously set itself to get rid of them. The law of Marcus
Aemilius Scaurus in 632, which at least enforced the constitutional
restrictions on the suffrage of freedmen, was for long the only
attempt--and that a very tame one--on the part of the senatorial
government once more to restrain their mob-tyrants.