Just to come back to this, it's only June, July and first half of August showing 5 daily Dublin. All other months up to October 2016 are showing 6 daily.
I think it was only dates in July I checked that made me originally think it was 5 x daily for the summer. Apologies.
Anyway, on the Ryanair web site (the old version as there seems to be a new one), the 6th flight shows as dropped from the 1 June but returning on 1st August.