anchor: for the unit pursuant to the emissions limitation requirements of this section applicable to the unit adjusted to reflect the unit's annual average fuel consumption on a Btu basis of any three consecutive calendar years between 1980 and 1989 (inclusive) as elected by the owner or operator and (B) the number of allowances allocated for the unit pursuant to the emissions limitation requirements of this  Provided, That the number of allowances allocated pursuant to this subsection shall not exceed an annual total of 40,000.
positive: The units of measurement were tracked over several calendar years.
negative: There was not a way to track emissions so they assumed they went over 50,000.