More info needed I'm afraid - is this plant in a pot or in the ground? Does it flower well every year? Which varieties of pear are they? Are, or were, the leaves healthy? And a photo of the tree might be helpful...

did you have hard frosts when they were in flower? if you did then that will be the cause of poor fruit set.

Does it get a lot of shade from the other trees? Are you sure that both varieties are still alive? By itself, a remaining variety may not be self fertile. If both are still alive, do they bloom at the same time? Again, it's about pollination.

Thank you for your help Bamboo Seaburngirl and Tugbrethil