Fil
Yes you are right. The numbers in the list refer to predicted retirement numbers based purely on the number of pilots reaching 55 each year. The numbers in brackets were the actual seniority increase of a junior pilot after ill health, retirees and part time bidders. A senior pilot would go up less as someone behind them might have left for various reasons.
Of course if things had gone on as before the list would have higher leaver numbers than listed each year.
Any expansion a/c will accelerate seniority a bit.
Not very well explained, sorry.