I know its some time after the last post, as I just joined the forum, but it
may be useful anyway.
The set up in the Peak (with the DCA) I imagine is similar in other regions
with P bolt placing. Because of the dreaded insurance aspect, P bolts can
only be placed and also inspected by certain nominated people. There is a
register of every bolt placed: when it was placed, exactly where, etc. In
effect every single bolt is uniquely identified and its history known. The
problem is that to maintain your status as a "qualified" placer or
inspector, you have to place at least one bolt each 12 months since the last
training session.
If there are say originally 10 people involved in placing/inspecting bolts
and assuming no new routes are bolted, there may only be a handful of bolts
needing replacement. Often one or two people end up doing this for one
reason or another (more time available or whatever).
Next thing you know, the 12 months have passed and only these one or two
people are left qualified to do all the work while the remainder try and
organise refresher training to bring the numbers back up.
That has happened in the Peak and possibly elsewhere.
Hope that helps.