Hi there Jo85, unfortunately unless someone here on this webiste works for upper management in recruitment, I dont think anyone can help you with your question, because we dont have statistics to view regarding the ratio of ex-cabin crew to new joiners.
If you are really worrying about this fact, then stop
because even though some of us are ex-flyers, we all had to begin somewhere and were once new joiners to this industry ourselves worrying about the same thing as you are.
Emirates are going to assess you more on how you present yourself(physically and mentally) at the interviews rather than previous flying experience.
There are also so many other skills taken into consideration for this position rather than just being an ex-flyer! For example....Previous nursing experience, customer service experience, language speakers etc, etc, etc.
I never got any free ticket because I had previous Cabin Crew experience, it was just as nail bitting for me as it was for everyone else in the interviews I attended. Im sure my past experience was factored in their decision somewhere down the line, but if I had of walked into the interview with an attitude that didnt fit and had not prepared for the interviews (and I worked hard studying information on the company, possible interview Q's etc) i certainly wouldnt be in dubai today typing out this response. (to make you feel a bit better, there were some ex-flyers at my interviews that weren't recruited)
So never mind about past flying experience, if you have it great, if you dont great again because each individual can bring something different to the role and its up to you to decide what colours you want to show your interviewers on the day....goodluck
Cheers