Those turnover numbers look unlikely to me.
A source told me recently that intake was >40 over the past 3 months.
I have no idea about attrition, but historically it has averaged 1% to 5% over the past couple of decades (with "hiccups" in 1999 with VSS and 2001 with the 49ers).
The highest turnover I can recall was a few years ago (2007??), with approximately 110 pilots leaving in one year. The total pilot body was about 2200 at the time, so this would be a loss of 5%.
I can remember attending a briefing at the time where a lady from recruitment stated that the pilot recruitment target for that year was approximately 200. The question as to whether recruitment targets factored in attrition, was neatly dodged. This was all starting to bite, when sadly Oasis folded...
I think the loss rate at that time was close to 10% across the road, which resulted in a shake-up and the demise of KA Cargo etc.