Like everything in BA it all depends whether you are in the right place at the right time!
Also depends on whether you want LGW WW or LHR WW.
I spent 2.5 years on LHR EF before transferring to WW, which I think is pretty average.
A friend of mine from the same initial course as me was prepared to go to LGW WW and it only took him 9 months!