even if you used 9/AC =4500 pilots for 250 AC or @2250 Captains and there is 2500 pilots here now, so if things stayed static 250 pilots here already will not be upgraded before 2020.5% attrition 125 /year , might be a bit high long term, 2.5% might be closer . Don't listen to those that claim there is going to be a mass exodus you will be disappointed when it does not happen and upgrades take longer