37.3. For the purposes of this division, except section 37.7, where an individual had more than one spouse during a year,(a) the individual is deemed to have had only one spouse during the year;
(b) the person who was the spouse of the individual on the last day of the year or, if the individual had no spouse at that time, the last person to have been his spouse during the year is deemed to have been the spouse of the individual during the year; and
(c) the individual is deemed not to have been the spouse during the year of any person other than the person referred to in paragraph b.