11 C.F.R. § 9004.2
(a) Candidate of a minor party in the preceding election. An eligible candidate of a minor party is entitled to pre-election payments:
(2) In an amount which is equal, in the aggregate, to a proportionate share of the amount to which major party candidates are entitled under 11 CFR 9004.1.
The aggregate amount received by a minor party candidate shall bear the same ratio to the amount received by the major party candidates as the number of popular votes received by the minor party Presidential candidate in the preceding Presidential election bears to the average number of popular votes received by all major party candidates in that election.