Have you been doing an annual retermination and sending a sample for destruct test? That will show the current state f the armour by comparing to its rated minimum breaking strain.
IMCA guidelines say the above should be done every 12 months.
I have seen them end for ended, however sometimes the first layer on the drum can be in a worse state than the soggy end that goes in the sea. If you are going to do it its also a good time to carry out a proper lubrication of the umbilical.