Ask an organisation how many reports it produces and you will often get an approximate answer. Ask how many are read and the answer is usually a much smaller number, offered with some embarrassment.
This happens for a reasonable reason. Reports are easy to add and awkward to remove, because removing one means telling somebody their request no longer matters. So the pile grows, and the genuinely useful numbers get harder to find inside it.
The fix starts from the other end. Rather than asking what data is available, ask what decisions people are trying to make, and work back to the smallest set of figures those decisions need. Everything outside that set is a candidate for retirement.
It also needs a named owner for each measure that survives. Without one, no disagreement about a definition can ever be settled, and the arguments come back within a year.