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 institution of a standing commission
regarding the exactions of magistrates in the provinces, occasioned
by the frequency of complaints as to such cases, in 605,(15) and
the laws as to extortion following each other so rapidly and
constantly augmenting its penalties, show the daily increasing
height of the evil, as the Nilometer shows the rise of the flood.
Under all these circumstances even a taxation moderate in theory
might become extremely oppressive in its actual operation; and that
it was so is beyond doubt, although the financial oppression, which
the Italian merchants and bankers exercised over the provinces, was
probably felt as a far heavier burden than the taxation with all
the abuses that attached to it.