Presently about 384 pilots and 16 a/c.
Capt/co approx. 50% so 12 captains and 12 co's per a/c.
Based on retirement at 65 and a steady expansion of 1 a/c per year up to a maximum of 25, the last one on the seniority list would get his/her upgrade in 2026.
To have an upgrade in 10 years 30 aircraft would be needed...