The “plus 90 days” in unnumbered paragraph following § 507(a)(8) applies only one time when three-year look-back is tolled during several prior bankruptcies. “[T]he phrase ‘plus 90 days’ applies . . . as a whole, singularly, regardless of the number of prior cases or plans. It would be an unnatural reading of this language to presume that the phrase ‘plus 90 days’ was meant to be multiplied where multiple prior bankruptcy cases exist. . . . The tolling event is the time during which enforcement of the claim is stayed. Plus 90 days.”