unless and until an adjusted administrative assessment is established pursuant to an adjustment proceeding under clause (iii). (iv) Adjustment of administrative assessment The administrative assessment may be adjusted by the Copyright Royalty Judges in a proceeding to occur no more than once every 2 years, in accordance with the following procedure: (I) The mechanical licensing collective, digital licensee coordinator, or one or more interested copyright owners, digital music providers or significant nonblanket licensees may file a petition with the Copyright Royalty Judges in the month of January to commence a proceeding to adjust the administrative assessment, if at least 2 years have expired since the date of the most recent determination of the administrative assessment by the Copyright Royalty Judges. (II) Notice of the commencement of such proceeding shall be published in the Federal Register in the month of February, along with a schedule of requested information and additional proceedings, as described in clause (iii)(III). The mechanical licensing collective and digital licensee coordinator shall participate in such proceeding, along with any interested copyright owners, digital music providers or significant nonblanket licensees that have notified the Copyright Royalty Judges of their desire to participate. (III) The adjusted administrative assessment, which shall be supported by a written record, shall be published in the Federal Register no later than 9 months after the publication of the notice of commencement of the adjustment proceeding. The adjusted administrative assessment shall take effect as of January 1 of the following year. (v) Adoption of voluntary agreements In lieu of reaching their own determination based on evaluation of relevant data, the Copyright Royalty Judges shall approve and adopt a negotiated agreement to establish the amount and terms of the administrative assessment that has been agreed to by the mechanical licensing collective, on the one hand, and the digital licensee