(1) The following persons are conclusively presumed to be dependents of a deceased person:

  (a) A wife is dependent on a husband with whom she lives at the time of his death.

  (b) A husband is dependent on a wife with whom he lives at the time of her death.

  (c) A child while under the age of 18 years, or over that age but physically or mentally incapacitated from earning, is dependent on the parent with whom he lives or from whom he receives support regularly at the time of the death of the parent.

  (2) In all other cases, questions of dependency and the extent of dependency shall be determined in accordance with the facts as they exist at the time of death.

  (3) The dependency of a surviving spouse terminates upon death or remarriage. The dependency of any other person terminates upon the death of the person and continues only so long as the person is under the age of 18 years, physically or mentally incapacitated from earning, or engaged full time in a formal program of academic or vocational education or training.

  (4) Personal protection insurance benefits payable for accidental bodily injury accrue not when the injury occurs but as the allowable expense, work loss or survivors’ loss is incurred.