Black Currant Getting Old?

My ten year old black currant bush has very little fruit this year - it is normally laden. 
I'm not sure how long-lived the plants are and wonder if this is the beginning of the end? It also has some branches that have died back this spring. It was pruned in winter as usual, and given a compost mulch when it first came into leaf and has had the usual grass clippings mulch since then. We had a warm winter & early spring with enough rainfall.
I have another dozen or so bushes all from cuttings which should start overwhelming us with fruit from next year so I'm not worried. But I won't bother feeding and mulching it if it's on its way out!

Cheers!