Ubetido, with a high strike rate method I would be looking at all up doubles, trebles etc. - starting a new all up with each bet.

Returns :

Flat stake 28 > 41.9
all up *2...28 > 62.9
all up *3...28 > 104.6
all up *4...28 > 163.8

A happy medium might be something like a third of a unit on each level of all ups which would return 110.4 for your 28 unit outlay.

Or maybe bet a partial all up e.g take out 25% each bet and bet the remainder.

Sounds like you have a reasonable sample of results so there are plenty of variations on this theme that you can look at - just run a few 'what ifs' and decide what suits your personal betting profile. (risk/reward)

The end result is that you must be happy with the method chosen - there is probably no right answer, just what is right for you.