Sof, it is a bit more complicated than that.

Just talking cross-country flights and only considering using FES to get home after having started (which is what I suspect you were getting at), I have only last year as a reasonable data set (illness andother things restricted my flying in 2011 and 2012 to few flights).

I did 17 cross-country flights in 2013and used the FES to get home on 3 or 4 of them. If 4, one was to be certain of crossing a big gap close to home and arriving with enough height to do a decent circuit/pattern, and avoid the risk of landing out in possible a bad field at the last moment.

But as well as those uses while completing flights, on 2 occasions I had winch launches, did not get a good thermal to climb away in time, and used the FES for a few minutes from about 700 feet to 1000 feet to avoid a relight - after which I climbed to a start height and returned to my start line (the home airfield) before doing an otherwise motorless flight. It is invaluable for such occasions too.

Then there were 5 other flights when it was barely soarable, certainly not good enough for cross country, but I used the motor locally - either just to keep in practice, or to do some flight tests to assess duration and climb rates (I have been doing some test flights as required by our airworthiness system and for feedback to Luka, the designer).

Dunno if this is what you wanted, but hope it helps.

Chris N