What is the average and range of business investments in Knowledge Management?

Please express as a percentatge of annual revenue, e.g., "Companies
invest  average X-XX% of annual revenue on knowledge management." (I
am particualaly interest in service and consulting companies, both
medium and large.)

The answer MUST be referencable.

Knowledge management consists of all systems, process, people and
methods use in the enterprise for learning, unstructured data,
communications (phone, email, IM, Fax, etc), collaboration and
increasing the overall knowledge of the firm.

It does NOT include the transactional systems (accounting, payroll,
benefits, etc.) from IT.