They are both still young and may find it hard to fruit each year.....
Did you feed them at all?
I consider it too late now to feed but a high potash feed in early spring may help....they can lose their blossom to early frosts though

Also it was a very cold wet spring which can deter blossoming.

There is also the possibility that these trees, like our plum trees, tend towards biennial/triennial fruiting. We had a good crop on ours last year, a splendid crop the year before, nothing the year before and not very much at all this year. They get the same pruning regime each year, and we are confident they'll give us good crops in the future. Of course, as Pam and MG have pointed out, a soggy cold spring won't have helped, not least in discouraging pollinating insects, either. Don't lose heart!