Originally Posted by PilotBases

The early March SL included the 3/2 class, so there were only 3 additional classes to be “added” for the April SL. To put it another way, the way the lists fell, there were five classes between Feb SL and March SL, and only 3 between March and April SLs. If you want to use the 1st of the month, then 3/2 gets added to April and makes the net change more similar.