Always call formula when an array for requested period doesn't exist yet: Don't interpolate array before calling formula.
Always call formula when an array for requested period doesn't exist yet: Don't interpolate array before calling formula.

adrienpacifico/openfisca-core,openfisca/openfisca-core,benjello/openfisca-core,openfisca/openfisca-core,benjello/openfisca-core,sgmap/openfisca-core