A renewal applicant involved in a comparative renewal proceeding shall receive a preference, commonly referred to as a renewal expectancy, which is the most important comparative factor to be considered in the proceeding, if its past record for the relevant license period demonstrates that the renewal applicant:
(a) Has provided ``substantial'' service during its past license term. ``Substantial'' service is defined as service which is sound, favorable, and substantially above a level of mediocre service which might just minimally warrant renewal; and
(b) Has substantially complied with applicable Commission rules, policies and the Communications Act.