Yes, that explains your finding. The FXCM API apparently composed price ticks in 2008-2010 in a different way than the ticks from more recent years. Possibly FXCM have filtered price quotes in some way before generating ticks from them.

I had not noticed this previously - I've only checked the 2013 data after your first post. I'll ask FXCM about that. We had downloaded the wickless price files in 2011, using their old API back then, so maybe unfiltered ticks are now available with the new API. We'll then upload new historic files soon.

- For overcoming the apparent confusion of quotes, ticks, bars, and candles, I'll put up a glossary of those terms in the manual. I hope this helps then to understand my clumsy technical explanations.