31. Every person who commits an offence contemplated in section 30 is liable,(1) in the case of a natural person, to a fine of $325 to $700;
(2) in the case of a legal person, to a fine of $700 to $1,400;
(3) for a first subsequent conviction, to a fine neither less nor more than twice the fines prescribed by paragraph 1 or 2, whichever is applicable;
(4) for any additional subsequent conviction, to a fine neither less nor more than three times the fines prescribed by paragraph 1 or 2, whichever is applicable.